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

The description adds a valuable behavioral guarantee beyond annotations: 'Renaming preserves all transaction associations.' This clarifies that a rename is non-destructive to related data, which annotations (readOnlyHint, destructiveHint) do not fully convey.

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?

Two short sentences with zero filler. The core action is front-loaded, and the important behavioral note about preserving associations is included without 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 simple update tool with no output schema axis, this description adequately covers what the tool does, what can be changed, and a key side effect. It omits details like return values, but those are not expected given the simplicity of the operation.

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?

With 0% schema description coverage, the description must compensate. It names two fields (name, color) and clarifies that either or both can be updated ('and/or'). However, tag_id (the required parameter) is not explained, though its role is inferable from the name.

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 clearly states the action ('Update a tag's name and/or color') with a specific resource and fields. It does not explicitly name alternatives like create_tag or list_tags, but the verb and resource make the tool's scope unambiguous.

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?

Usage context is implied: this tool is for modifying an existing tag's name or color. No explicit when-to-use or when-not-to-use guidance is provided, nor are alternatives mentioned, but the description is clear enough for an agent to infer the appropriate scenario.

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