contacts_update

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

Annotations already declare readOnlyHint=false, openWorldHint=true and destructiveHint=false, so the mutation/safety profile is covered. The description adds the useful distinction that only the provider's copy is changed, but says nothing about reversibility, whether the old name is retained, or failure behavior for a non-existent contact.

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 core purpose is front-loaded in one sentence; the transport parenthetical (POST path, gRPC method, socket name) is extra but compact and potentially useful for debugging. No filler or redundancy.

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 3-required-parameter mutation with 33% schema coverage and no output schema, the description should clarify the identifiers and the effect of the rename. Instead it leaves channelId/contactId undefined and gives no expectations about the response or error cases.

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 only 33%: channelId and contactId carry bare examples with no documented meaning, and the description does not compensate for that gap. The 'provider's own records' phrasing loosely echoes the publicName note ('the platform is NOT told') but adds no semantics for the two undocumented identifiers.

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 ('Rename a contact') and adds a scope qualifier ('in the provider's own records'), which is enough to distinguish it from contacts_create/contacts_delete. It does not explicitly contrast with the closest sibling contacts_update_status, leaving differentiation partly to the reader.

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?

No indication of when to use this over contacts_update_status or contacts_sync, no prerequisites (e.g., the contact must already exist), and no note on which records are affected. The reader must infer everything from the name.

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