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

Adds substantial context beyond the annotations: no address number is supplied so Collmex assigns one, existing addresses are never overwritten, repeated calls create duplicates, and nothing is sent to the person (no mailings triggered). It also discloses the return value (new address number) despite there being no output schema.

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?

Front-loads 'WRITE:' and the core action, then layers scope, duplicate risk, side effects, and validation in a tight paragraph. Every sentence carries distinct information with no repetition of schema or annotation content.

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 16-parameter write tool with no output schema, the description covers the mutation model, idempotency behavior, minimum-viable input, side effects, and return value. Nothing an agent needs to invoke it safely is missing.

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 coverage is 100% so field-level meaning is already covered, but the description adds a genuine cross-parameter constraint absent from the schema (which declares zero required fields): at least a company or a last name must be given. That is real 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?

States a specific verb (create) and resource (Collmex address book entry) and pins down the exact record type and semantics (CMXADR, address type 3). It also distinguishes itself from the read path by naming collmex_list_addresses, so an agent can route without opening the schema.

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?

Gives an explicit pre-condition workflow: check collmex_list_addresses first to avoid duplicates, and warns that every call creates another entry. The one gap is that it never contrasts with the sibling collmex_create_customer, which an agent could plausibly confuse for a person/company record.

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