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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=true, and openWorldHint=false, so the safety profile is largely carried by structured data. The description adds the schema-lookup prerequisite but does not disclose a key behavior for a destructive mutation: whether omitted fields are preserved or cleared, or what happens to fields not supplied. That is a meaningful gap given destructiveHint=true.

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?

Two short sentences, front-loaded with the core action and followed by the one actionable prerequisite. No waste, though the second sentence largely duplicates the custom_fields schema text rather than adding new information.

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?

An output schema exists and the annotations plus 100%-covered input schema are rich, so much of the burden is off the description. Still, for a destructive, idempotent update tool with a required id and nullable owner field, the description omits partial-update semantics and failure behavior, leaving it only minimally complete.

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 baseline is 3. The description only reinforces the crm-schema requirement already stated in the custom_fields schema description and adds no new semantics (e.g., partial-update behavior, null handling for account_owner_id) beyond what the schema already documents.

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 ('Update an existing company in the CRM'), which cleanly separates it from create-company-tool and delete-company-tool. It does not explicitly name any sibling, but the verb/resource pair is unambiguous against the many other update-*-tool siblings.

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?

It gives one concrete operational prerequisite — read the crm-schema resource before using custom_fields — which is genuinely useful routing guidance. However, it offers no when-to-use vs. when-not guidance (e.g., when to use get-company-tool first, or that this only updates vs. creates), leaving usage context implied.

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