estimate_cost

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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It states the tool estimates costs, implying a non-mutating calculation, but does not reveal whether it makes network calls, how the estimate is computed, what the return format is, or any side effects. For a tool with 10 parameters, this is insufficient.

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 a single, front-loaded sentence of under 15 words. It contains no fluff and efficiently communicates the core purpose, achieving high clarity per word.

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 tool is complex (10 params, no output schema, no annotations), yet the description provides only a minimal one-sentence purpose. It gives no information about expected inputs, output structure, or behavioral nuances, making it wholly inadequate for an agent to invoke the tool correctly.

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?

The input schema has 0% description coverage, and the tool description does not explain any of the 10 parameters. Required fields like size, files, and complexity are not mentioned, and even the enums (XS/S/M/L, low/medium/high) are left undocumented. The description fails to compensate for the schema's lack of semantics.

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 uses a specific verb ('Estimate') and identifies the resource ('Anthropic API token costs') and context ('for a development plan before execution'). This clearly distinguishes it from sibling tools that report or record costs, making its purpose 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?

The phrase 'before execution' provides clear contextual guidance for when to use this tool, implying it is for planning rather than after-the-fact reporting. However, it does not explicitly name alternative tools or state when not to use it, so it falls short of the highest bar.

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