Update a contact field

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

The description goes beyond the annotations (destructiveHint=true) by specifying exactly what gets deleted: options omitted from the list are removed along with the values contacts hold for them. It also explains the uuid-based behavior (kept/relabelled vs created) and the immutability of type/slug. This adds meaningful context about side effects and aligns with the idempotentHint and destructiveHint without contradiction.

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 two paragraphs, front-loading the primary action in the first sentence. The second paragraph adds necessary detail about option handling and constraints. It is concise with no fluff, though the option behavior sentence is dense and could be slightly clearer with structure (e.g., bullet list).

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?

The description covers the core behaviors: rename, option replacement with deletion semantics, and immutability of type/slug. It does not mention prerequisites like obtaining profileUuid or fieldUuid, but these are likely standard for reach tools. Given no output schema, return values are not needed. Overall, adequate for an agent to call it correctly, with minor gaps in prerequisite guidance.

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?

Although the schema descriptions are generic for label, fieldUuid, and profileUuid (e.g., 'label parameter'), the tool description clarifies the label as the new name and explains the options parameter's replacement and deletion semantics in detail. It also implies fieldUuid identifies the field to update. This adds value beyond the schema, especially for the options parameter which already has a descriptive schema comment.

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 states a specific verb and resource: it renames a custom contact field and, for choice types, replaces its option set. This clearly distinguishes it from sibling tools like create, delete, and list contact fields. The note that field type and slug cannot be changed further defines its scope.

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 description implies usage for renaming or replacing options, but does not explicitly contrast with create or delete. The limitation 'field type and slug cannot be changed' implicitly suggests not using this tool for those changes, but it does not point to alternatives or mention prerequisites such as fetching UUIDs via list endpoints. Guidance is only partial.

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