LibrePass eSIM

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds no behavioral context at all – nothing about what 'details' includes, error behaviour for unknown ids, or rate limits – so it earns little credit beyond not contradicting the annotations.

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

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

A single well-formed sentence that front-loads the purpose and embeds the id source and examples. Nothing is wasted.

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

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

For a one-parameter read-only lookup with rich annotations, this is close to sufficient. The only gap is that, with no output schema, the description never hints at what fields the package details contain.

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

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

Schema coverage is 100% and the single parameter is already described as 'Package id from list_packages'. The description adds genuine value beyond the schema by giving concrete id-format examples ('tr-10gb-30d', 'tr-daily-3gb'), which helps the agent construct or validate the argument.

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

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

States a specific verb/resource pairing ('Details of one package') and even names the sibling that produces the required id ('the id that list_packages returned'). It stops short of an explicit 'use X instead' routing statement, but an agent can distinguish it from list_packages without opening the schema.

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

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

The precondition is clear: this tool is for when you already have an id obtained from list_packages. There is no statement of when-not to use it or a named alternative for other lookups, which keeps it at 4 rather than 5.

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

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds real content beyond that: it enumerates what each package record contains (data volume, validity, speed, EUR price with VAT, daily plans, monthly pool, networks) and notes the returned page URL, which is exactly the kind of payload context annotations cannot convey.

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

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

A single dense sentence that front-loads the purpose and then lists the payload fields; nothing is wasted, though the enumerated field list runs long and 'the monthly pool' is vague phrasing.

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

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

For a read-only, single-parameter listing tool with full annotation coverage and no output schema, the description covers purpose and returned content well. Minor gap: it does not say whether results are paginated or how an invalid/unknown country is surfaced.

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

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

Schema description coverage is 100% and the single country parameter is fully documented with format examples ('tr', 'TH', 'United Kingdom'), so the baseline is 3. The description only echoes 'for one country' and adds no syntax or resolution guidance (e.g. that names are accepted, or to use search_countries).

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

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

States a specific verb and resource ('List the eSIM packages') plus the scope ('for one country'), which is enough to distinguish it from get_package (single retrieval) and search_countries. It never names the siblings explicitly, so it stops short of a 5.

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

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

Usage is only implied: an agent can infer this is the browse-plans-for-a-country step, but the description gives no explicit when-to-use, no exclusions, and no routing to get_package for details or search_countries to resolve a country id.

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

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds real context beyond that: a hard cap of 10 results and that each match carries an id plus an eSIM-availability signal. It stops short of stating ordering or empty-result behavior, which matters slightly for an open-ended name query.

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

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

Two sentences, zero filler, with the primary purpose first and the return shape second. Nothing repeats the name or title verbatim.

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

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

For a one-parameter read-only lookup with no output schema, the description covers what it does, what it returns, and the result cap. The only gap is not saying what an empty result means (unknown country vs. no eSIM coverage) — a minor but real ambiguity for a lookup tool.

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

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

Schema coverage is 100% and the single parameter's description already gives examples ("Turkey", "TH"), so the schema does the heavy lifting. The description's "by name or ISO code" corroborates but adds nothing new — e.g. no note on partial/fuzzy matching or case sensitivity for name lookups, which is the one ambiguity a caller would actually hit.

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

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

Specific verb + resource ("Find countries") plus the secondary purpose of checking eSIM availability, which is the actual business question. The result cap and id field are stated, so an agent knows exactly what comes back without opening the schema. Siblings (package/registration tools) operate on different resources, so no confusion arises.

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

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

Usage is implied by the wording — a lookup-by-name-or-code tool used before checking packages or registration rules — but there is no explicit "use this when…", no mention of what to do on zero matches, and no pointer to list_packages or sim_registration_rules as the follow-up step. Adequate, not instructive.

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

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real value beyond that: it discloses that responses include an official source and check date, and flags that content is general information rather than legal advice — a useful caveat for downstream use.

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

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

Two sentences, front-loaded with the substantive answer scope and closed with the disclaimer. No filler; the phrasing is slightly telegraphic but every clause contributes.

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

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

For a read-only single-param lookup with no output schema, the description effectively describes the returned content (requirements, registrant, document, consequences, source, date). What remains unstated — output shape/format and error behavior for unknown countries — is minor.

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

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

Single parameter with 100% schema description coverage ('Country id, ISO code or English name'), so the schema carries the semantics. The description adds nothing about accepted country formats or fallback behavior, which is the baseline 3 case.

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

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

The description enumerates precisely what the tool answers: whether registration is required, who must register, which document, and consequences. That is a specific resource with defined output scope, and it is clearly distinct from the sibling package/country tools. It lacks an explicit verb ('returns'/'looks up'), which keeps it short of a 5.

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

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

Usage is implied by the topical framing (SIM registration per country), but there is no statement of when to prefer this over siblings or any exclusion. The 'not legal advice' line hints at scope but not at routing.

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