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taxme-mcp

Read and fill your Canton of Bern tax return (TaxMe / BE-Login). Drafts only — submission is gated.

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Unofficial, and inherently fragile. This drives a web portal with a real browser because the service offers no retrieval API. Portal updates break selectors without warning, and a broken selector means a failed run rather than a wrong result. It is published because it is useful, not because it is guaranteed — pin a version, read the errors, and expect to update. Use it for your own account and respect the provider's terms of service.

An MCP server for the Canton of Bern tax portal TaxMe / BE-Login (belogin.directories.be.ch). From any MCP client (Claude Code, Claude Desktop, …) you can read your account statement and your tax returns, and navigate and fill a return — open it, walk the menu sections, read the fields on a page, set values, click buttons and read the tax calculation.

What it is (and the SwissID / AGOV constraint)

BE-Login has no public API and authenticates through SwissID / AGOV (the Swiss government login, incl. 2FA). There is no headless way in: the login is an interactive browser flow you have to complete yourself. So this server drives the real portal with Playwright browser automation. Two consequences:

  • You log in once, in a visible browser window (taxme_login). Everything after that runs headless against the session you established.

  • It is inherently fragile. Portal releases can change page structure and break selectors; the server uses text/URL-based selectors with fallbacks, but expect occasional breakage after a TaxMe update.

It is full-featured: besides reading, it can open a return, walk the menu, read fields, fill them (text / radio / checkbox), click buttons (Neuen Eintrag erfassen, Speichern, Nächste Seite …) and read the results.

Safety: the server only fills drafts. The final submission (taxme_submit_return) is gated behind an explicit confirm: true; without it you get a dry-run of the Abschluss page and nothing is submitted.

Private use, for your own BE-Login account only. Respect the portal's terms of use.

Related MCP server: elster-mcp-server

Prerequisites

  • Node.js ≥ 20.19 (node --version).

  • Install dependencies and a Chromium build for Playwright:

    git clone git@github.com:sapn95/taxme-mcp.git
    cd taxme-mcp
    npm install
    npx playwright install chromium   # downloads a Chromium into the Playwright cache

    npx playwright install chromium is required unless a Playwright Chromium is already cached on the machine. See Troubleshooting if the browser can't be found.

Session model — log in once, stay logged in

The whole point of this server is that you don't re-login every time.

  1. Run taxme_login once. A visible Chromium window opens; complete the SwissID / AGOV login (incl. 2FA) yourself. The server waits up to ~8 minutes.

  2. The session is cached two ways so it survives server restarts:

    • a persistent Chromium profile in ~/.taxme-mcp/profile (keeps the trusted-device state, so AGOV doesn't re-prompt 2FA), and

    • the full session — including session cookies — mirrored to ~/.taxme-mcp/state.json via Playwright storageState() after login and after every successful call.

  3. On startup the server re-seeds a fresh browser context from state.json, so the AGOV session keeps working across restarts until it genuinely expires.

  4. When it does expire, any tool returns {"status": "login_required"} — just run taxme_login again.

So the normal flow is: taxme_login once, then use the read/edit tools freely; re-login only when you actually get login_required.

flowchart TD
    C["MCP client"] -->|"stdio JSON-RPC"| S["taxme-mcp"]
    S --> Q{"Is the cached<br/>session still good?"}

    Q -->|"yes"| DRIVE["Playwright drives<br/>the TaxMe portal"]
    Q -->|"no"| LR["every tool answers<br/>login_required"]

    LR --> LOGIN["taxme_login<br/>visible window, waits ~8 min"]
    LOGIN --> ME["you complete SwissID / AGOV yourself —<br/>2FA, or one Touch ID on an<br/>installed, signed browser"]

    DRIVE --> R[("BE-Login → TaxMe")]
    ME --> R

    DRIVE -.->|"after every successful call"| ST
    ME -.->|"after login"| ST

    subgraph disk["on disk — live cookies for your tax account"]
        P["profile/<br/>keeps the device trusted,<br/>so AGOV stops re-prompting 2FA"]
        ST["state.json<br/>Playwright storageState"]
    end
    disk -.->|"re-seeded into a fresh<br/>context on startup"| Q

    classDef secret fill:#fdecea,stroke:#c0392b
    classDef you fill:#fff4e5,stroke:#d9822b
    class P,ST secret
    class ME,LOGIN you
    style disk fill:#fbfbfb,stroke:#999,stroke-dasharray: 4 3

The two red boxes are the reason the section below says what it says: both hold live cookies for your tax account, and anyone holding them is you until the session expires.

Security: state.json (and the profile/ directory) contain live session cookies for your tax account. They are secrets. Both are in .gitignorenever commit or share them. Anyone with state.json can act as you on the portal until the session expires. Delete them to force a clean logout.

Override the locations with env vars if you want:

Variable

Default

Purpose

TAXME_PROFILE

~/.taxme-mcp/profile

browser profile dir (holds the session — secret); empty = a throwaway profile

TAXME_STATE

~/.taxme-mcp/state.json

cached storageState json (session cookies — secret); empty = don't cache the session

TAXME_BROWSER

auto-detect

chrome, chrome-canary, edge, brave, chromium, or an absolute path

TAXME_CHROMIUM

legacy alias for TAXME_BROWSER

TAXME_BASE_URL

the real portal

portal base URL; exists so the test suite can drive a local fixture instead of a real taxpayer's account

TAXME_WAIT_SCALE

1

scales the fixed pauses that wait for TaxMe to rebuild the page, and nothing else — no timeout is derived from it. Only shortens: anything that is not a finite number in (0, 1] is ignored, and no scaled pause goes below 25 ms. Exists for the same reason as TAXME_BASE_URL — a fixture has nothing to rebuild

A variable that is set, even to the empty string, is authoritative: an empty TAXME_STATE means no session cache, not "fall back to the default one". Anything else would make "no session" impossible to express — and would let a test that thought it was isolated quietly open the real account.

Which browser, and why it decides how you log in

BE-Login authenticates through SwissID/AGOV, and the browser is not a matter of taste: Playwright's bundled Chromium reports isUserVerifyingPlatformAuthenticatorAvailable() === false, so the portal never offers a passkey and falls back to password plus SMS. An installed, signed browser reports true and can reach the macOS platform authenticator, which turns the same login into one Touch ID confirmation.

The server therefore prefers an installed system browser — chrome, chrome-canary, edge, brave, in that order — and only falls back to the bundled Chromium. Override with TAXME_BROWSER (a key from that list, chromium, or an absolute path); TAXME_CHROMIUM still works as an alias.

For the underlying detail, including why a software passkey cannot be used at all, see the write-up in private-routines/reference/swissid-login.md.

Register a passkey once in Safari or Chrome under your SwissID account settings; after that the portal offers it ahead of the password.

Register in Claude Code

From the repo directory, register the server for your user (use an absolute path to index.js):

claude mcp add taxme --scope user -- node /absolute/path/to/taxme-mcp/index.js

That writes an entry into ~/.claude.json. Equivalent manual snippet:

{
  "mcpServers": {
    "taxme": {
      "command": "node",
      "args": ["/absolute/path/to/taxme-mcp/index.js"]
      // optional:
      // "env": { "TAXME_STATE": "/custom/path/state.json" }
    }
  }
}

Restart Claude Code (or reconnect the MCP server), then run the taxme_login tool once to establish the session.

Other MCP clients (Claude Desktop, etc.) take the same command / args in their own MCP config.

Tool reference

Read / session

Tool

Args

Purpose

taxme_status

ok or login_required

taxme_login

open a visible window for the SwissID/AGOV login (waits up to ~8 min); caches the session. Only status: "ok" means the login went through — the login page is served on the portal's own address, so being there proves nothing, and the portal is asked afterwards whether anybody is actually logged in. A login that was never completed comes back as login_required and nothing is cached

taxme_account_statement

open amounts (CHF) per tax year — Kantons-/Gemeindesteuern, direkte Bundessteuer, Gemeindeabgaben. A statement prints a due date under every claim, and the 2024 assessment falls due in 2025, so an amount is only reported under a year the page itself puts it under; when none can be, you get status: "unparsable" rather than an empty list that would read as nothing owed. A page that is not a Kontoauszug at all — a maintenance notice, an error page — is unparsable too: an empty list of open amounts is only ever reported when the statement itself is on the page

taxme_list_returns

tax returns (Steuererklärungen) with status (In Bearbeitung / Quittiert …). An empty list is only reported when the case list itself is on the page: a page that is not one — a maintenance notice, an error page — and a list whose rows carry no year we could tie them to are both status: "unparsable", because there is nothing to file must not be concluded from a page that was never asked the question

Navigate & edit a return

Tool

Args

Purpose

taxme_open_return

year (number)

open a return for editing; returns the menu sections (handles the edit popup tab). Only status: "ok" means it is open — the tab that appears is checked against the year you asked for, so an expired session comes back as login_required, a page that is no return as not_open, and a different case as wrong_year with the year the portal actually opened

taxme_menu

left-menu sections + status of the open return. The menu is on every page of a return and on no other page, so a page carrying none is no return: that comes back as an error naming where the browser is, not as an empty list of sections. taxme_goto_section, taxme_results and taxme_submit_return say the same thing about the same page, rather than reporting a section they cannot find

taxme_goto_section

name (string)

click a menu section by name (substring); returns its fields — cut at 60 like taxme_get_fields, and saying so with truncated/total. Landing there is checked: TaxMe refuses to open a section while the form still has errors, and the page it hands back instead is reported as an error naming the section you are really on — not as that section's fields under the name you asked for. Which section that is is decided by the menu entry the breadcrumb names, not by the requested name turning up somewhere in it: these names nest both ways round ("Wertschriften" sits at the front of "Wertschriftenverzeichnis", "Einkünfte" at the end of "Übrige Einkünfte"), so a substring test says yes on the wrong page. A breadcrumb is a path and the page is the end of it, so it is read as a path: the entry it names is the one in the last of its steps that names any entry at all, and within that step the longest, since a longer name that fits contains every shorter one nested inside it. A breadcrumb that names no entry at all, or one that is a shortened form of the name that was clicked — an entry that name begins with — is ambiguous and is not read as a refusal; any other entry is a different page and is. A page with no menu on it at all is no return, and says so

taxme_get_fields

limit (number)

interactive fields on the current page (id, type, value, label, context, name for a radio — the group, i.e. the one question, its button belongs to — and locked when the portal has switched the field off); long forms are cut at limit (default 60) and the reply says how many were left out

taxme_snapshot

screenshot (bool)

breadcrumb + url of the current page; screenshot: true writes a PNG and returns its path

taxme_fill

values: [{target, value}]

set fields — target = field id or a label/context substring; value must be text, a number or true/false; text→typed, radio→option value or label, checkbox→true/false (ja/nein, 1/0, on/off are understood too). An option neither a radio group nor a dropdown has is refused with a list of the ones it does, rather than attempted. Every value is read back after it is set and compared with what was asked for, so a widget the portal re-renders and hands back unchanged — a radio left unanswered, a dropdown back on another option or on none — comes back as ok: false rather than as set. fields_after is cut at 60 too, and says so

taxme_click

label (string)

click a button/link by visible text (Neuen Eintrag erfassen, Speichern, Nächste Seite, Vorherige Seite, Ändern …); an exact label wins, a substring is the fallback, and clicked names the button that was actually pressed. An empty or blank label is refused rather than resolved: a substring that is empty matches every element on the page, so it would press whichever button happens to come first

taxme_results

read the Ergebnisse / Steuerberechnung of the open return. Reaching that section is a precondition, and it is settled the way taxme_goto_section settles it — by the menu entry the breadcrumb names — before a word of the page is read as a calculation: a portal that refused to open the section comes back as an error naming the page you are actually on, not as that page's text. That check stands down on a breadcrumb naming no entry of this menu, and where it has settled nothing the page itself has to say the section is open before an amount is read off it: the calculation is only ever read from a line the word heads — never from the left-menu entry, which is on every page of the return — and, without a breadcrumb naming the entry, only when that line is a heading of the page (a heading tag, a legend, a caption, a title/header panel) rather than a sentence beginning with the same word. A refusal banner can be written either way round in German, so word order is the portal's phrasing and not evidence about which page is open. And if the click landed somewhere carrying no menu — an expired session lands on the login form — that is reported as no return being open, not as a page with no calculation on it

Submit (gated)

Tool

Args

Purpose

taxme_submit_return

confirm (bool)

⚠️ DANGER — irreversible final submission (Abschluss → Steuererklärung einreichen). Without confirm: true it only opens the Abschluss page and returns a dry-run naming in would_click the one button a confirmed call would press; nothing is submitted. Reaching that page is a precondition — with no submit button on it the call is refused instead of pressing whatever the current page offers. A page that already reports the return as filed (already_submitted) is refused as well, confirm: true and all: a confirmation that was on the page beforehand cannot prove anything about a second click. So is a page whose text could not be read at all (page_unreadable), for the same reason one step further back — a read that failed is not a page that said no — the submit button is then named as not_clicked, because would_click is a promise about the confirmed call and that call presses nothing. And a page carrying no menu is no return at all — the Abschluss entry links to the edit view, and a session that died in the meantime is bounced to the login form — which is said in those words instead of reporting the Abschluss page as merely not open, the shape a portal refusing it over a form error has. Only confirm: true actually files the return.

A typical edit session: taxme_logintaxme_list_returnstaxme_open_return {year}taxme_goto_section {name}taxme_get_fieldstaxme_fill {values}taxme_click {label: "Speichern"}taxme_results.

JSF quirks handled

TaxMe is a JSF (JavaServer Faces) app with a few sharp edges the server already smooths over, so you don't have to:

  • Radio buttons are set by clicking the associated <label>, falling back to a JS click() + a dispatched change event — plain .check() on the input doesn't reliably trigger JSF's listeners. In taxme_fill a radio value may be the option value or its visible label. The button is read back afterwards: a JSF group is re-rendered by the server when it hears the change and can come back unanswered, and an answer that did not stick must not be reported as given.

  • Switched-off widgets. A section can be Ausgeschaltet aufgrund Ihrer Eingaben, and its inputs are then disabled. The browser never submits a disabled input, so taxme_fill refuses one (locked: "disabled") instead of setting it in JavaScript and reporting a value the portal will never receive.

  • Amounts are whole francs. Enter 12000, not 12000.00 / 12'000. The form drops the centimes silently, so taxme_fill reads every value back and returns a warning when the field ended up holding something other than what it was given — a wrong number in a tax return should not look like a success.

  • The edit popup tab: opening a return spawns a new browser tab; taxme_open_return waits for and switches to that popup, and the other edit tools always target the live edit tab automatically.

  • JSF component ids are unstable across releases, so selectors are text/URL-based with fallbacks.

Troubleshooting

  • {"status": "login_required"} — the session expired (or you never logged in). Run taxme_login and complete SwissID/AGOV in the window that opens. This is normal and expected periodically.

  • The login window doesn't appear / login can't completetaxme_login runs headed on purpose (AGOV needs interaction). It must run on a machine with a display; it won't work over a headless/SSH session with no desktop. Everything else runs headless.

  • Chromium not found — install it with npx playwright install chromium, or point TAXME_CHROMIUM at an existing Chromium/Chrome-for-Testing binary. The server auto-detects the Playwright cache (~/Library/Caches/ms-playwright/chromium-* on macOS).

  • Everything says login_required even right after logging in — your state.json / profile may be stale or corrupt. Delete ~/.taxme-mcp/state.json (and, if needed, ~/.taxme-mcp/profile/) and run taxme_login again.

  • Selectors broke after a portal update — TaxMe changed its markup. Use taxme_snapshot { "screenshot": true } and taxme_get_fields to see the current page, and open an issue.

  • Only Canton of Bern. Other cantons use different portals; this server is TaxMe-specific.

Releasing

Published from CI with npm Trusted Publishing (OIDC) — there is no npm token anywhere: no secret to store, rotate or leak. npm recommends this over an automation token, and is restricting tokens that bypass 2FA.

One-time setup per package, on npmjs.com -> the package -> Settings -> Trusted Publisher:

Field

Value

Organization or user

sapn95

Repository

taxme-mcp

Workflow filename

release.yml

Allowed actions

npm publish

The workflow filename must match exactly. That is deliberate: it stops any other workflow in the repo from publishing under your name.

Then every release is one command:

npm version patch && git push --follow-tags

The tag triggers the release workflow: it upgrades npm (trusted publishing needs

= 11.5.1 and Node >= 22.14), refuses a tag whose version disagrees with package.json, runs the gate, and publishes with a signed provenance statement.

If the publish fails with 404

npm notice publish Signed provenance statement ... from GitHub Actions
npm error 404 Not Found - PUT https://registry.npmjs.org/taxme-mcp

Provenance was signed, so OIDC worked — the registry simply does not accept this workflow as a publisher yet. That means the trusted publisher is not configured, or the repository / workflow name does not match. npm answers 404 rather than 403 so as not to reveal whether the package exists. It is not a credential problem: there is no credential, by design.

Checks

npm run gate      # syntax, lint, smoke, hygiene, tests with coverage floors
npm test          # the test suite alone
npm run coverage  # the suite plus the enforced coverage thresholds
npm run mutate    # mutation-test the lines this branch changed

npm run gate is what CI runs. It needs a Chromium (npx playwright install chromium), because the tests drive the real automation rather than a mock of it.

How the portal is tested without a portal. test/fixture-portal.mjs is a local HTTP server that serves the DOM the automation depends on, including the traps that made it what it is: a radio whose <input> is invisible so only its label can be clicked, a second radio group with no label that swallows the click and commits only on a dispatched change, a checkbox the portal has switched off that can still be ticked from JavaScript but never submitted, element ids with colons in them, an amount field that drops the centimes, a return that opens in a second tab (and one that comes back as the login page, as a maintenance page, or as a different tax year), menu entries and buttons that are prefixes of each other, a radio group the server re-renders and hands back unanswered, a section the portal refuses to open so that the overview you were on comes back with a banner, a Kontoauszug whose due dates print years that are not headings (and a Kontoauszug link that answers with no Kontoauszug on it at all), and a session cookie whose absence shows up as a perfectly normal-looking page saying Angemeldet als: Benutzer. TAXME_BASE_URL points the server at it, so no test can reach the real BE-Login. Every assertion about a click or a submission is made against what the fixture received, not against what the server reported.

The submission gate has its own file: test/safety.test.mjs calls taxme_submit_return without confirmation, with confirm:false, and with every value that looks like consent but is not the boolean ("true", 1, "yes", ["true"]), and asserts each time that the fixture received nothing. The last test in that file confirms with confirm:true and checks that a submission does arrive — otherwise the six tests above it would prove nothing.

The smoke test completes the MCP handshake over stdio and asserts the things that have actually broken here — a server version drifting from package.json, a tool in the dispatcher but missing from the tool list (or advertised and unhandled), a required property absent from a schema, and descriptions too thin to choose a tool from. The hygiene scan refuses secrets, tracked session files and personal identifiers.

Roughly 90% of index.js is covered. The rest is mostly the callbacks handed to Playwright's evaluate(): they execute inside Chromium, so Node's coverage never sees them run — they are exercised, just not counted.

Mutation testing

npm run mutate asks a different question from everything above: not "do the tests pass" but "would they notice if a guard were removed". StrykerJS deletes one piece of behaviour at a time and reruns the suite; whatever survives is something no assertion is watching.

It found eleven real gaps in the sibling pingen-mcp after model review rounds had stopped turning anything up. Here it runs over the lines a branch changed rather than the whole file, because this suite drives a real browser once per mutant and a full pass costs hours. npm run mutate:all does the whole file if you have the time; stryker.config.json explains every setting that is not a default, including why incremental mode is off.

License

MIT © sapn95

Available Tools

13 tools
taxme_account_statementA

Open tax amounts (CHF) per tax year. Amounts are only reported under a year the statement itself puts them under; if none can be, the answer is status "unparsable" rather than an empty list that would read as nothing owed. A page that is not a Kontoauszug at all — a maintenance notice, an error page — is "unparsable" too: an empty list is only reported when the statement itself is on the page.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

A4.2/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure and does so exceptionally well. It explains critical edge cases: amounts are only reported under the year the statement assigns, and if none can be assigned, the status is 'unparsable' rather than an empty list. It also clarifies that non-statement pages (maintenance, error) are 'unparsable', preventing misleading empty-list interpretations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences, with the first stating purpose and the next two providing essential edge-case behavior. Every sentence adds value, though it is slightly more verbose than strictly necessary. The information is front-loaded and no unrelated details are included.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a parameterless tool with no output schema, the description is remarkably complete. It defines the primary output (tax amounts per year), the meaning of 'unparsable' status, and the distinction between empty list and unparsable. This is sufficient for an agent to correctly interpret results, especially given the lack of structured output annotations.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so there is nothing for the description to add beyond the empty input schema. Baseline for zero parameters is 4, and the description does not need to explain parameter semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The first sentence clearly states the tool's function: 'Open tax amounts (CHF) per tax year.' This is a specific verb+resource pairing that distinguishes it from sibling tools like listing returns or getting fields. The subsequent sentences further clarify scope by describing how amounts are attributed.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It does not mention sibling tools, exclusion conditions, or prerequisites. The only implied usage is 'when you need tax amounts per year,' which is tautological and not helpful for tool selection.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_clickA

Click a button/link by visible text (e.g. "Neuen Eintrag erfassen", "Speichern", "Nächste Seite", "Vorherige Seite", "Ändern"). An exact label wins; failing that a substring matches, and the reply names the button that was actually pressed. An empty or blank label is refused rather than resolved — an empty substring matches every element on the page, so it would press whichever button comes first.

ParametersJSON Schema
NameRequiredDescriptionDefault
labelYes

TDQS

A4.8/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden and exceeds expectations. It discloses the exact match preference, substring fallback, reporting of the actually pressed button, and the refusal of empty labels with reasoning. This is rich behavioral context beyond the bare minimum.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose, then adds necessary details and examples without redundancy. Every sentence contributes value—examples clarify usage, and the empty-label warning prevents misuse. It is concise yet comprehensive.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter tool with no output schema or annotations, the description is complete. It covers what the tool does, how it behaves in ambiguous cases, and how errors are handled. No relevant aspect is missing, making it fully self-contained for an agent to invoke correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema only provides a 'label' string with no description, so the description fully compensates. It explains that the label is the visible text, gives examples, and details the matching semantics (exact vs substring) and the empty-label edge case, making the parameter meaning unambiguous.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's action: 'Click a button/link by visible text', which is a specific verb and resource. It provides concrete examples of labels and distinguishes itself from sibling tools like taxme_fill by focusing on clicking existing elements, not filling or navigating.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context for when to use the tool (clicking any button/link by visible text) and includes examples of typical labels. It does not explicitly name alternatives or exclusions, but the scope is well-defined and easily inferred from the examples and the nature of the action.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_fillA

Set fields on the current page. Each value: {target, value}. target = field id OR a label/context substring. value must be text, a number or true/false — text→typed (use whole francs for amounts), radio→option value or label, checkbox→true/false (ja/nein, 1/0 and on/off are understood too). A value that is neither a yes nor a no, an option neither a radio group nor a dropdown has (the reply lists the ones it does), and a field the portal has switched off are all refused rather than guessed at, and every value is read back afterwards and compared with what was asked for — a radio the portal hands back unanswered, and a dropdown it hands back on another option or on none, come back as ok:false, not as set.

ParametersJSON Schema
NameRequiredDescriptionDefault
valuesYes

TDQS

A3.9/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description fully carries the transparency burden. It discloses detailed behavior: how different value types are interpreted (text, radio, checkbox), what gets refused (invalid values, disabled fields), and the verification process (read-back and ok:false if mismatch). This is rich behavioral context that goes beyond basic expectations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, lengthy run-on sentence that packs in a lot of information but is poorly structured. It could be broken into clearer sentences or bullet points for readability. Every piece of information is relevant, but the format hurts comprehensibility.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity of the tool (multi-field form filling with target resolution, value mapping, refusal conditions, and verification), the description covers all major aspects. It does not describe the full reply structure but does mention ok:false. It is complete enough for an agent to invoke the tool correctly with no output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema only defines a generic 'values' array with 'target' and 'value', but the description adds crucial semantic meaning: target can be a field id or label/context substring, and value must be text/number/boolean with type-specific handling. Since schema coverage is 0%, this description fully compensates and even exceeds what the schema provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the verb+resource: 'Set fields on the current page.' It is specific enough to distinguish from other tools like taxme_click or taxme_menu, though it does not explicitly name any alternatives. The meaning is unambiguous and matches the tool name.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not provide guidance on when to use this tool versus alternatives, nor does it mention prerequisites or exclusions. It only implies usage on a page with fields, but there is no explicit 'use this when...' or comparison with sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_get_fieldsA

List interactive fields on the current page (id, type, value, label, context, name for a radio — the group, i.e. the one question, its button belongs to — and locked when the portal has switched the field off; a locked field takes no value). Long forms are cut at limit (default 60) and the reply says how many were left out; taxme_fill still resolves against every field.

ParametersJSON Schema
NameRequiredDescriptionDefault
limitNohow many fields to return (default 60)

TDQS

A4.4/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries full burden. It discloses truncation behavior (limit, default 60), that the reply reports omitted fields, the meaning of 'locked', and that taxme_fill still sees all fields. This goes well beyond a simple 'list fields' statement.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single information-dense and front-loaded sentence, but it becomes a bit run-on with parentheticals and semicolons. Every clause earns its place, yet splitting into two sentences would improve readability.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite having no output schema, the description fully covers what the tool returns (list of fields with specific attributes), the limit behavior, the locked concept, and the interaction with taxme_fill. This is complete for a low-complexity read-only tool with one parameter.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% for the single 'limit' parameter, so baseline is 3. The description adds behavioral semantics: limit causes truncation and the reply states how many were left out, which the schema alone does not convey.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description starts with 'List interactive fields on the current page' – a specific verb and resource. It enumerates the field attributes (id, type, value, label, context, radio group name, locked) and distinguishes itself from siblings by referencing taxme_fill behavior.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied (use this to see fields on the current page) but no explicit when-to-use or alternatives are given. The mention that taxme_fill resolves against every field hints at a workflow but does not state 'use this before filling' or contrast with sibling tools like taxme_snapshot.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_goto_sectionA

Click a menu section by name (substring) in the open return; returns the fields on that page, cut at 60 like taxme_get_fields and saying so with truncated/total. Landing there is checked: TaxMe refuses to open a section while the form still has errors, and the page it hands back instead comes back as an error naming the section you are really on — not as that section's fields under the name you asked for. Which section that is is decided by the menu entry the breadcrumb names, not by the name appearing somewhere in it, because these names nest both ways round ("Wertschriften" at the front of "Wertschriftenverzeichnis", "Einkünfte" at the end of "Übrige Einkünfte"). A breadcrumb is a path and the page is the end of it, so it is read as a path: the last of its steps that names an entry of this menu, and within that step the longest entry, since a longer name that fits contains every shorter one nested inside it. A page carrying no menu is no return at all — an expired session lands on the login form — and comes back as an error saying so.

ParametersJSON Schema
NameRequiredDescriptionDefault
nameYes

TDQS

A4.7/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Without annotations, the description carries full responsibility for behavioral disclosure, and it excels. It details substring resolution via breadcrumb paths, error handling for form validation and expired sessions, and the truncation behavior ('cut at 60... with truncated/total'). This goes far beyond a basic operation description.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is dense and lengthy, but it is front-loaded with the core action in the first sentence. Every subsequent sentence adds necessary nuance for a complex matching algorithm and error scenarios. It is appropriately sized for the complexity, though not as crisp as a simpler tool's description.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the single parameter, no annotations, and no output schema, the description covers all essential aspects: operation, output format (fields with truncation), error conditions (form errors, expired session), and resolution logic. It also references taxme_get_fields to clarify output behavior, making it effectively complete for an agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The only parameter 'name' receives extensive semantic explanation: it is a substring that must match a menu entry as determined by breadcrumb resolution, with examples ('Wertschriften' at front, 'Einkünfte' at end). This adds tremendous meaning beyond the bare schema string type, especially given 0% schema description coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's primary function: 'Click a menu section by name (substring) in the open return; returns the fields on that page.' This specific verb+resource combination distinguishes it from siblings like taxme_menu (which lists sections) and taxme_get_fields (which fetches fields without navigation).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context by specifying 'in the open return' and notes a critical precondition: 'TaxMe refuses to open a section while the form still has errors.' It does not explicitly name alternative tools or when-not-to-use scenarios, but the context is clear enough for an agent to select this tool for section navigation.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_list_returnsB

Tax returns with status. An empty list is only reported when the case list itself is on the page: a page that is not one — a maintenance notice, an error page — and a list whose rows could not be read are both status "unparsable", because "there is nothing to file" must not be concluded from a page that was never asked the question.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

B3.2/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly discloses that 'unparsable' status may indicate a maintenance/error page or unreadable rows, and warns against concluding 'nothing to file' from such a page. This is valuable, but it doesn't cover other possible behaviors like pagination, return format, or side effects.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, run-on sentence packing multiple ideas. It front-loads the core purpose ('Tax returns with status') but then adds a lengthy, awkwardly structured clarification. Splitting into two sentences would improve readability without losing information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has no parameters, no output schema, and no annotations, the description covers the critical edge case of empty vs. unparsable. However, it omits useful context such as possible status values, result ordering, or any requirements. It is adequate but not exhaustive.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so there is nothing for the description to add beyond the schema. The baseline score of 4 applies as the schema fully covers parameter information.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Tax returns with status' identifies the resource (tax returns) and the information provided (status), clearly implying a listing operation. The additional nuance about empty vs. unparsable results clarifies the tool's output semantics. However, it lacks an explicit verb like 'list' and does not differentiate from sibling tools such as taxme_status.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites like being logged in, nor does it contrast with sibling tools such as taxme_status or taxme_open_return. The entire focus is on interpreting the output rather than usage context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_loginA

Open a visible window for the SwissID/AGOV login (waits up to 8 min). Only status "ok" means the login went through: the portal is asked afterwards whether anybody is logged in, because the login page is served on the portal's own address and being there proves nothing. A login that was never completed comes back as login_required, and nothing is cached.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

A4.7/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It goes beyond a simple statement: it explains the visible window, the up-to-8-minute wait, the post-login status check, the reason for asking the portal, and that nothing is cached. This is rich, honest transparency about the tool's behavior and limitations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise yet informative. It front-loads the core action, then provides essential caveats in two follow-up sentences. Every sentence adds value: the visible window, the timeout, the meaning of 'ok', and the caching behavior. No wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter, no-output-schema tool, the description is remarkably complete. It explains the tool's purpose, its blocking behavior, expected outcomes ('ok', 'login_required'), and a key nuance about the portal address. There is no missing information that would prevent an agent from using or interpreting the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so the baseline is 4 according to the rubric. The description does not need to explain parameters, but it does add contextual meaning about the login flow, which indirectly clarifies what the tool does despite having no inputs.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's action ('Open a visible window for the SwissID/AGOV login') and distinguishes it from sibling tools like taxme_status or taxme_get_fields by focusing on the authentication step. The verb+resource structure is specific and unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use (at the start of a session requiring login) and provides critical guidance on interpreting the result ('Only status "ok" means the login went through'). It does not explicitly name alternatives or exclusions, but no direct alternative exists among the siblings, and the guidance is sufficient for correct usage.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_menuA

Left-menu sections of the open return with their status. A page carrying no such menu is no return: that comes back as an error naming where the browser is, not as an empty list of sections.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

A3.5/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the responsibility for behavioral disclosure. It usefully explains that a non-return page yields an error naming the browser location rather than an empty list. However, it does not state whether the operation is read-only or how the successful response is structured, leaving some transparency gaps.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise, consisting of two short sentences. The core purpose is front-loaded, and the second sentence adds a valuable edge case without wasted words. It is appropriately sized for a zero-parameter tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no parameters and no output schema, the description covers the essential output (sections and status) and an important error condition. It could be more detailed about the exact response format or possible status values, but the essentials are sufficient given the tool's simplicity and the surrounding sibling context.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so the description does not need to explain parameter meanings. The baseline score of 4 for zero-parameter tools applies here.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description identifies the resource as 'left-menu sections of the open return' and mentions their status, which is specific and distinguishes it from sibling tools like taxme_status. However, it lacks an explicit verb like 'get' or 'list', so it is clear but not perfectly framed.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no explicit guidance on when to use this tool versus alternatives. It implies it operates on the 'open return' but does not state prerequisites or contrast with other tools. No exclusions or alternative tool references are given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_open_returnA

Open a tax return (year) for editing; returns the menu sections. Handles the edit popup tab. Only status "ok" means the return is open: the page is checked against the year that was asked for, so a login page or another case comes back as login_required / not_open / wrong_year instead.

ParametersJSON Schema
NameRequiredDescriptionDefault
yearYes

TDQS

A4.3/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description thoroughly explains expected statuses (ok, login_required, not_open, wrong_year) and the verification against the requested year. It also notes handling of the edit popup tab, adding useful behavioral context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences only, front-loaded with purpose and outcome. Every word adds value; no fluff or repetition of schema fields.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter tool with no output schema, the description covers purpose, return value (menu sections), and all possible status outcomes, making it fully self-contained for an agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has no descriptions, so the description carries the burden. It identifies 'year' as the tax return year and explains it is used for page verification, but does not specify format or constraints beyond the schema's type.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it opens a tax return for editing and returns menu sections, using a specific verb and resource. It is distinct from sibling tools like taxme_status or taxme_list_returns.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides clear context for when to use (to open a tax return for editing), but does not explicitly name alternative tools or exclusion conditions. The implied use case is evident from the description.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_resultsA

Read the Ergebnisse / Steuerberechnung of the open return. Reaching that section is a precondition, and it is settled the way taxme_goto_section settles it — by the menu entry the breadcrumb names — before a word of the page is read: a portal that refused to open the section comes back as an error naming the page you are really on instead of that page's text. A breadcrumb that names no entry of this menu settles nothing there, though, and where it has settled nothing the page itself has to say the section is open before an amount is read off it: the calculation is only ever read from a line the word HEADS — never from the left-menu entry, which is on every page of the return — and, absent a breadcrumb naming the entry, only when that line IS a heading of the page (a heading tag, a legend, a caption, a title/header panel) rather than a sentence beginning with the same word, since a refusal banner can be written either way round and word order is the portal's phrasing, not evidence about which page is open. A click that landed on a page with no menu at all — an expired session lands on the login form — is reported as no return being open, not as a page carrying no calculation.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

A4.1/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It reveals several key behaviors: the requirement to have the section open via breadcrumb, the error behavior when the portal refuses (returns the actual page name), the rule that the calculation is only read from a line containing HEADS and only when that line is a heading element, and the handling of expired sessions (reports no return open). This is rich behavioral disclosure.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness2/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single dense paragraph with many nested clauses. While the first sentence is clear, the rest is a long, convoluted explanation of edge cases that could be broken up or summarized. It is not concise or easily scannable.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the main purpose, preconditions, error cases, and the specific rule for identifying the calculation line. However, it does not explicitly describe the return value format beyond implying it reads an amount. Given the absence of an output schema, this is a minor gap, but overall the tool is well-contextualized.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so there is nothing to document beyond the schema. The baseline for 0-param tools is 4, and the description doesn't need to add parameter details.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a clear statement: 'Read the Ergebnisse / Steuerberechnung of the open return.' This specifies the verb (read), the resource (Ergebnisse/Steuerberechnung), and the scope (open return). It distinguishes from sibling tools like taxme_get_fields and taxme_snapshot by focusing on the calculation section.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies the tool is for reading the tax calculation once the section is open, but it does not explicitly state when to use it versus alternatives. It mentions preconditions (reaching the section) but does not name any alternative tools or exclusion criteria. Thus, usage is implied rather than explicitly guided.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_snapshotA

Current page breadcrumb/url; set screenshot:true for a PNG path.

ParametersJSON Schema
NameRequiredDescriptionDefault
screenshotNo

TDQS

A3.5/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the burden of behavioral disclosure. It states the primary output (breadcrumb/url) and the optional screenshot behavior, but does not mention side effects, error cases, or what happens if no page is loaded. The behavior is largely read-only, but this is not explicitly confirmed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single sentence with a semicolon, conveying both the default behavior and the optional flag. Every word is purposeful with no redundancy or filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with only one optional parameter and no output schema, the description provides the essential information: what information is returned and how to request a screenshot. However, 'breadcrumb/url' and 'PNG path' are ambiguous (e.g., is it a local file path or a URL?), leaving minor gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single boolean parameter 'screenshot' is described in the description ('set screenshot:true for a PNG path'), adding meaning beyond the bare schema. The schema covers the parameter type, but the description clarifies its functional effect, which is helpful given the low schema description coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states that the tool provides the current page's breadcrumb/url and optionally a PNG screenshot path. It effectively distinguishes itself from sibling tools by focusing on page-state retrieval, though it lacks an explicit verb like 'get' or 'return'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is given on when to use this tool versus alternatives. It does not mention that taxme_status or other navigation tools might be more appropriate for certain scenarios, nor does it state any prerequisites or exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_statusA

Check whether the BE-Login/TaxMe session is alive (ok) or an interactive SwissID/AGOV login is needed (login_required). Call this before anything else; it also refreshes the cached session.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

A4.5/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden. It discloses the side effect of refreshing the cached session and explicitly indicates the possible return values. It doesn't mention error states or authentication details, but for a simple status check this is adequate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is exactly two sentences, front-loaded with the main purpose, and includes the key usage instruction. Every word adds value with no redundancy or filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the zero-parameter tool and no output schema, the description fully covers what the tool does, what it returns, when to call it, and a key side effect. It is complete for an AI agent to invoke correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters and the input schema is empty, so the baseline is 4. There is no parameter information needed; the description appropriately focuses on behavior and usage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool checks the BE-Login/TaxMe session status and returns 'ok' or 'login_required'. This specific verb and outcome, plus the instruction to call it before anything else, distinguishes it from siblings like taxme_login and taxme_list_returns.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'Call this before anything else' provides explicit when-to-use guidance. While it doesn't name alternative tools or specify when not to use it, it clearly positions this as the initial health check, which is sufficient context given the sibling list.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

taxme_submit_returnA

DANGER: final submission (Abschluss → Steuererklärung einreichen). Irreversible. Requires confirm:true; otherwise returns a dry-run of the Abschluss page, naming in would_click the one button a confirmed call would press. Reaching that page is a precondition: if no submit button is there, the call is refused rather than pressing whatever the current page happens to offer. A page that already reports the return as filed (already_submitted) is refused too, confirm:true and all — a confirmation that was on the page beforehand could not prove anything about a second click. A page whose text could not be read at all (page_unreadable) is refused for the same reason one step further back: a read that failed is not a page that said no. In both cases the submit button is named as not_clicked rather than would_click, because nothing would be pressed. And a page carrying no menu at all is no return — an expired session lands on the login form — which is said in those words rather than as the Abschluss page merely not being open.

ParametersJSON Schema
NameRequiredDescriptionDefault
confirmNo

TDQS

A4.7/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries full burden and does so impressively. It discloses irreversibility, dry-run behavior when confirm is false, the would_click/not_clicked distinction, and every refusal case including expired sessions. This goes far beyond basic operation and fully informs the agent of all safety behaviors.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single verbose paragraph, but every sentence communicates a distinct edge case or behavioral rule, earning its place. It is longer than ideal, but the high stakes justify thoroughness. Minor deduction for lack of structural formatting like bullet points.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity of an irreversible submission, no annotations, and no output schema, the description is exceptionally complete. It covers preconditions, response outcomes (dry-run vs actual click), and all refusal scenarios, leaving the agent well-equipped to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema only defines a boolean 'confirm' with no description. The description explains that confirm:true is required for actual submission, and false triggers a dry-run, adding meaning that is absent from the schema. Since schema coverage is 0%, this is essential and well-handled.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with 'DANGER: final submission' and 'Abschluss → Steuererklärung einreichen', clearly indicating this tool performs the final tax return submission. It is distinctly different from sibling tools by emphasizing irreversibility and the submit button, leaving no ambiguity about what action it performs.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit preconditions: the user must be on the Abschluss page and confirm must be true. It also details when the tool refuses to act (already submitted, page unreadable, no menu). However, it does not explicitly name alternative sibling tools for other contexts, so it lacks direct comparative guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

  1. 13 tool updatesv0.5.0
    • First observedtaxme_account_statement
    • First observedtaxme_click
    • First observedtaxme_fill
    • First observedtaxme_get_fields
    • First observedtaxme_goto_section
    • First observedtaxme_list_returns
    • First observedtaxme_login
    • First observedtaxme_menu
    • First observedtaxme_open_return
    • First observedtaxme_results
    • First observedtaxme_snapshot
    • First observedtaxme_status
    • First observedtaxme_submit_return

TDQS

A4.1/5.0

Scored across 13 tools

Disambiguation5/5

Each tool targets a distinct action or resource: status/login handle session, account_statement/list_returns/open_return manage tax data, menu/goto_section/get_fields/snapshot navigate and inspect, fill/click modify, results reads calculations, submit_return finalizes. No two tools have overlapping purposes; descriptions reinforce the boundaries.

Naming Consistency4/5

All names share the taxme_ prefix and use snake_case, but the pattern mixes verb-noun forms (list_returns, open_return, get_fields) with noun-only forms (status, menu, snapshot, results). This is mostly consistent and predictable, with minor deviations.

Tool Count5/5

13 tools is well-scoped for a tax filing automation server. Each tool addresses a necessary step in the workflow—from session management to form interaction to submission—without redundancy or bloat.

Completeness5/5

The tool surface covers the full lifecycle: login, status check, listing returns, opening returns, navigating sections, reading fields, filling values, clicking buttons, viewing results, and submitting. There are no obvious dead ends or missing critical operations for the stated purpose.

Maintenance

ActivityActive
ResponsivenessNo issues

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