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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description complements them by explaining that company_imo is the company's own IMO rather than a vessel IMO, which is a meaningful behavioral nuance. It also lists the profile fields returned, going beyond the annotation safety profile.

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 front-loaded with the core purpose, then covers returned fields, search methods, the critical company-vs-vessel distinction, and the alternative tool in three concise sentences. Every sentence earns its place with no fluff or repetition.

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?

Given the rich annotations, complete 100% schema coverage, and an existing output schema, the description provides all the context an agent needs to select and invoke the tool correctly. It covers purpose, parameters, scope, and the key disambiguation from intel_ownership.

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 fully documented in the schema. The description reinforces the company_imo distinction, but this information already appears in the schema's parameter notes, so the description adds limited additional semantic value beyond the structured data.

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 ('Look up a maritime company profile') and enumerates the returned fields. It also distinguishes itself from intel_ownership by clarifying this is a company directory, not a vessel lookup, making sibling differentiation explicit.

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 description explicitly tells the agent when to use this tool ('Search by the company's own IMO number or by name') and when not to: 'to find the companies behind a specific ship use intel_ownership.' This provides clear context and a named alternative, leaving no ambiguity about the intended use case.

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