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

Annotations include destructiveHint:true, and the description adds the HTTP method PATCH and the partial-update behavior. It does not contradict the destructive hint; it reinforces that this is a write operation. No further behavioral details are provided, but the annotation covers the main risk.

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 extremely concise: one sentence explaining the update semantics and another giving the REST endpoint. Every word adds value, with no redundancy or 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?

Despite having no output schema, the description provides the essential context: it is an update (PATCH) for an existing company, with partial-update semantics. Combined with full parameter schema and annotations, it is sufficient for an update tool, though it omits return value and error behavior.

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%, with each parameter having a descriptive text (e.g., 'X/Twitter URL (sent as xLink:{primaryLinkUrl})'). The tool description itself adds no parameter-level details beyond the schema, so a baseline of 3 is appropriate.

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 clearly states the action ('Update fields') and resource ('existing company'), and specifies the REST endpoint 'PATCH /rest/companies/{id}', distinguishing it from create/get/list siblings which use different verbs and resources.

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 phrase 'Only provided fields change' explicitly communicates a partial-update semantic, telling the agent when to use this tool (update existing company with specific fields). It does not explicitly mention alternatives, but sibling names like 'create_company' and 'get_company' make the use case clear without extra guidance.

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