Brick Broker

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

Annotations already cover read-only, idempotent, non-destructive, and closed-world behavior, so the description's added context is the 'Uncached' note — a meaningful freshness guarantee not expressible in the annotation set. It also discloses the enumerated status values and that price is in USD, beyond what the annotations carry, but says nothing about behavior for an unknown or malformed id.

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 front-loads the resource and its returned fields with no filler. The trailing one-word fragment 'Uncached.' is slightly awkward as a standalone sentence, but it carries real information rather than padding.

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 lookup with no output schema, the description usefully substitutes for one by naming the returned fields and the possible status values. The main remaining gap is error/not-found behavior, which matters for a lookup keyed on an id an agent may have guessed or copied incorrectly.

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?

With a single parameter at 100% schema description coverage, the schema already explains the UUID/slug format, pattern, and length limits. The description's repeat of 'by item UUID or slug' adds no constraint or nuance beyond the structured field, so baseline 3 applies.

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 ('Return'), an explicit scope ('one public listing'), and enumerates exactly what comes back: status (available, sold, Available Soon), USD price, and product URL. The singular-item scope cleanly separates it from sibling search_sets, which handles multi-result search.

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: the 'one listing ... by item UUID or slug' phrasing signals a point lookup on an already-known item rather than a search. No explicit when-to-use/when-not statement or named alternative appears in the description, though the parameter schema does point to search_sets for obtaining ids.

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?

The annotations already disclose that this is a read-only, idempotent, non-destructive, non-open-world operation. The description adds useful business behavior beyond that: US-only support, included ground shipping, and the fact that no reservation or purchase occurs. It does not describe error behavior or return shape, so it is not fully transparent.

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?

The description is three short, front-loaded sentences with no redundant wording. Each sentence contributes either purpose, supported-country behavior, or a non-mutation clarification.

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 simple two-parameter read-only quote tool with rich annotations and 100% schema coverage, the description covers purpose, supported destination, and non-purchase behavior. Because there is no output schema, it could say more about the returned quote format or currency, but the omission 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?

Schema description coverage is 100%, so the parameters are already fully documented in the input schema. The description only restates that the tool takes a public listing and a two-letter country code, without adding syntax, formatting, or default details beyond the schema.

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 states a specific verb and resource: 'Return the shipping quote for one public listing and a two-letter country code.' It is clearly distinct in domain from check_availability, read_policies, and search_sets, but it does not explicitly name or differentiate those siblings.

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?

It gives clear usage constraints: US ground shipping is $0 extra, other countries are unsupported, and the call does not reserve or buy. It does not explicitly route the agent to or away from sibling tools, which keeps it below a 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, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds only that the result is unstructured text rather than a formatted object, which is mildly useful but no more; nothing is said about freshness, locale, or whether unpublishable policies are omitted.

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 front-loaded sentence with no filler; the resource and return format are stated immediately and nothing is repeated from the title or schema.

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 zero-parameter, read-only tool with no output schema, the description is nearly complete: it says what comes back (text) and which policies are included. The only missing piece is what happens when a policy has not been published, which would matter for interpreting an empty or partial result.

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?

The tool takes zero parameters, so there is no parameter meaning to convey and the baseline of 4 applies. The description correctly implies a single fixed retrieval with no filtering or selection knobs available.

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?

"Return the shop's published ... policies as text" gives a specific verb and resource and enumerates the exact policy categories (shipping, returns, sales-tax, Verified Complete). None of the siblings (check_availability, quote_shipping, search_sets) overlap with policy retrieval, so an agent can place it without opening the schema, though the description never states that distinction explicitly.

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?

No explicit when-to-use or when-not-to-use guidance is given; usage is only implied by the subject matter (call it when a buyer asks about shipping, returns or tax terms). With such an obvious, non-overlapping scope the inference is easy, but the description does no routing work of its own.

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, so the safety profile is covered. The description adds useful return-shape detail (paginated items with title, set number, condition, price, availability, URL) but says nothing about total counts, page limits beyond schema, or empty-result behavior.

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 purpose then return shape. No filler. Slightly compressed to the point where filter interaction details are omitted, but structurally clean.

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?

A read-only search tool with full schema documentation and no output schema; the description covers purpose and return fields, which is sufficient. Missing only edge-case behavior (empty query results, pagination limits) that would help an agent loop through pages.

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% with per-parameter descriptions and enums, so the schema carries the semantics. The description only summarizes filter categories (category, theme, condition, USD price) without adding meaning beyond the schema, which matches the baseline 3.

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 ("Search public LEGO listings") plus the searchable fields and the return contents. It distinguishes itself from siblings like check_availability and quote_shipping implicitly, but doesn't name them or explain the boundary explicitly.

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 description — search listings, then presumably use check_availability or quote_shipping for follow-ups — but no explicit when-to-use/when-not or alternative routing is stated. An agent must infer the workflow from sibling names alone.

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