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

Annotations already establish readOnlyHint, idempotentHint, and non-destructive behavior, so the bar is lower. The description adds genuine context beyond annotations: the HTTP method and endpoint (GET /v1/companies/:id), the per-call cost ($0.05), and the cross-source identity semantics. No description-annotation contradiction.

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?

One dense sentence with the method, endpoint, and cost front-loaded, followed by a scannable field enumeration. The 'plus aggregate stats' grouping cleanly separates profile fields from statistical fields. No filler, though each clause earns its place rather than being minimal.

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 moderately complex read tool with one required parameter, strong annotations, and no output schema, the description covers the essentials: what is returned (profile fields and aggregate stats), how it is keyed, and what it costs. The remaining gap is response structure detail, but the explicit enumeration of return groups mitigates the absence of an output schema.

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% — id ('numeric id from search results', exclusiveMinimum 0), client_key, and payment_token are all documented in the schema. The description only reinforces that id is the lookup key ('by id') and adds no syntax, format, or default detail beyond the schema, so the baseline of 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?

The description states a specific verb and resource ('Company profile by id') and enumerates the payload contents: name, country, NIF, aliases, source identifiers, and aggregate stats. This is clear and specific, and the content list implicitly separates it from siblings like get_company_awards and get_company_opportunities, though it never names them 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 id' — you need a company id to fetch its profile), and the id parameter notes ids come from search results. However, there is no explicit when-to-use versus alternatives: nothing says to prefer get_company_awards for award lists or get_company_opportunities for opportunity feeds, and no exclusions are stated.

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