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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered by structured fields. The description adds genuine value beyond them: it discloses partial-update semantics ('only the fields you pass are sent') and the overwrite consequence for those fields, and restates the PUT endpoint consistent with idempotentHint.

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?

Three tightly packed fragments with the mutation flag front-loaded. The overwrite rule is stated before the endpoint, and nothing is wasted or repeated from the 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 9-param mutation tool with annotations covering safety, full schema coverage, and no output schema, the description is nearly complete. It covers write intent, partial-update behavior, and the endpoint; only error/permission behavior on an invalid id is absent, which is minor here.

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 schema fully documents all nine parameters including the required company_id. The description adds no syntax, format, or constraint 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?

States a specific verb and resource ('change fields of one company') and leads with 'WRITE:' to mark it as a mutation. It implicitly differentiates from sibling update tools by resource type, but never names an alternative (e.g., create_company or get_company), so sibling routing is left to inference.

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: an agent understands this updates an existing company. There is no explicit when-to-use vs when-not, no mention of the create/read siblings, and no prerequisites (e.g., needing a valid company_id). The partial-update note leans toward behavior rather than selection guidance.

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