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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description does not need to repeat safety traits. It adds value by listing return fields and emphasizing read-only nature implicitly. No contradictions; minor gap in explaining that it requires valid slug.

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 two sentences plus a usage note, all front-loaded. Every sentence serves a purpose: action, output, when to use, and caution against guessing. No fluff.

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 get-by-slug tool with one parameter and no output schema, the description sufficiently covers what the tool does, what it returns, and prerequisites (knowing slug from search). The usage note addresses the main ambiguity.

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 single parameter 'slug' has full schema coverage at 100%. Description adds meaning by defining slug as 'the last path segment of its profile URL' and providing an example. This helps the agent understand the parameter format beyond the schema description.

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?

Description clearly states 'Fetch a single agency's full profile' and specifies the input (slug) and output fields (description, location, rating, services, website, reviews). It distinguishes from siblings by focusing on a single agency vs search/matching.

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?

Explicitly states 'WHEN TO USE: after search_agencies or match_agencies...' and warns 'Don't guess slugs - find them via search_agencies first.' Provides clear context for when to invoke this tool.

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