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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds no behavioral context such as response shape, pagination, or what 'custom field values' includes.

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 short but the first sentence is duplicated verbatim, which is pure waste, and the useful content (operation ID and the describe_operation pointer) is buried after the repetition rather than front-loaded.

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 tool with nested parameters, zero schema description coverage, and no output schema, the description leaves the agent without any information about what 'query' accepts, what the response looks like, or how this differs from the sibling custom-fields definition endpoint. It is effectively incomplete.

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 0% for two parameters (a nested 'params.id' path parameter and a freeform 'query' object), and the description provides no explanation of either. Because the schema carries no descriptions, the description had to compensate and does not.

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 just repeats the endpoint path 'GET /api/contracts/:id/custom-fields/values' twice, which restates the tool name and title rather than explaining what the operation returns or why an agent would call it. An agent can guess it reads custom-field values for a contract, but that comes from the path text, not from any stated purpose.

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 only actionable guidance is a pointer to describe_operation for native request schemas, which implies the tool is a thin proxy. There is no statement of when to use this versus the many sibling tools such as get_contracts_by_id_custom_fields_defin or get_contracts_by_id_custom_sections.

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