estimate_sts_cost

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the agent knows this is a mutating but non-destructive open-world operation. The description adds that it saves an STS quote and does not synthesize, but provides no auth requirements, rate limits, or other behavioral details beyond the annotations.

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 poorly structured, with display-layer instructions such as 'Show only display.estimated_costs' that are unlikely to help an agent invoke the tool. The purpose sentence is not clearly front-loaded, and the final 'Does not synthesize' feels tacked on.

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 cost-estimation tool with five parameters, low schema coverage, and no output schema, the description is incomplete. It does not explain what the tool returns, how costs are calculated, or how the parameters affect the estimate, leaving major gaps for an agent.

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 coverage is only 20%; only voice_id has a schema description, while speech_asset_id, stability, similarity, and exaggeration are undocumented. The description does not compensate by explaining any of these parameters, mentioning only vague concepts like 'selected entitlement' and 'billable characters/seconds' without mapping them to inputs.

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 says it saves an STS quote via backend preview and does not synthesize, which gives a rough sense of an STS cost/preview tool. However, the verb 'Save' conflicts with the tool name 'estimate_sts_cost' and leaves the core purpose ambiguous. It does distinguish from generate_sts but does not clearly state it estimates costs.

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?

There is no positive guidance on when to use this tool versus estimate_tts_cost or other estimation siblings. The only usage hint is the negative 'Does not synthesize,' which excludes generate_sts but does not tell the agent when this tool is appropriate.

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