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

Annotations cover the safety profile (destructive, idempotent, not read-only). The description adds real context the annotations don't: ambiguity returns candidates rather than guessing, last write wins, existing runs unchanged, and re-running re-charges credits. The credit-charging on re-run is particularly valuable since the agent might assume idempotency means free.

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-loaded with the core action, followed by exactly two sentences that each earn their place: the ambiguity-resolution workflow and the side-effect warnings. No filler.

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 mutation tool with destructive annotations and an output schema (which handles return values), this covers what the agent needs: how ambiguity is handled, what state is affected, and cost implications. Could say more about what 'pin' does to the node's existing configuration, but the essentials are there.

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%, so the schema documents all four parameters well. The description reinforces the omission pattern for locale/model (only pass them when the tool asked for them via candidates) but doesn't add syntax or format details beyond the schema. Baseline 3 applies.

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: 'Pin a catalog voice onto one locale of a workflow's generator node.' An agent can immediately tell this differs from siblings like preview_voice, find_voices, or patch_workflow.

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 a clear conditional: if a locale/model/generator is ambiguous, the tool returns candidates and you call again with that argument. This is actionable. It doesn't explicitly state when not to use it vs. preview_voice, but the write-vs-preview distinction is implied.

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