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

Adds real value beyond the annotations by disclosing non-idempotency (each call creates a new record) and the underlying POST endpoint. It does not go further into permissions, duplicates, or what the response contains, but the key behavioral trait of repeated calls is covered.

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 short clauses, front-loaded with the write marker and the non-idempotency caveat; nothing is wasted. It is slightly telegraphic and uses an endpoint reference that adds little for an agent choosing a tool.

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?

A simple 4-parameter create tool with a complete schema and no output schema; the description covers mutation semantics, uniqueness behavior, and the endpoint. It could mention whether a created ID is returned, but nothing needed to call it correctly 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 description coverage is 100% and all four fields are documented in the schema, so the description need not repeat them. It contributes nothing extra about parameters, so baseline 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?

States a specific verb and resource ('create a new customer') that clearly separates it from the get_/list_ customer siblings. It doesn't name a sibling explicitly, so it falls just short of the top mark.

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 'WRITE:' prefix and the 'not idempotent' warning imply this is the tool for creating records, but there is no explicit when-to-use statement, no alternative named, and no exclusions. Adequate but thin.

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