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

Beyond the readOnly/idempotent/non-destructive annotations, the description discloses the auth requirement, the no-upload guarantee for both input modes, and the safety profile ('Never charges, never runs an audit, never stores anything'). It also adds nuanced behavior: the default quote is 'the exact price a real call makes at that moment', and content-free manifests return an 'honest upper-bound pass count... clearly marked as an estimate'.

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 information-dense and front-loaded with the most critical facts: the key requirement and the no-upload promise. Each sentence adds a distinct fact (inputs, outputs, default tier, fullScan behavior, estimate honesty, guarantees). There is some redundancy — no-upload is restated three times and the never-charges/never-stores guarantee twice — but the emphasis is reasonable for a tool whose core value is trust.

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?

With no output schema, the description compensates by fully listing the return values (tier, passes, price, balance, coverage), and it documents the estimate upper-bound behavior for manifest-only calls. With 100% parameter coverage, 4 params, and no nested objects, the main gap is the absence of failure-mode descriptions (missing/invalid key, unreachable repo URL, what an error response looks like) — minor for a read-only estimation tool.

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 100%, setting a baseline of 3, but the description adds meaning beyond the schema: it explains that fullScan changes which tier is quoted and ties it to what 'a real call charges', and it frames the files manifest as 'paths and byte sizes you would post' with no content. This enriches the agent's understanding of how the parameters affect the quote.

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 title and description name a specific verb-resource pair — estimate an audit's price — and enumerate the exact outputs: tier (Audit or Full Audit), passes, exact price, credit balance, and coverage status. It distinguishes itself from the audit execution siblings by repeating the no-upload differentiator ('nothing is uploaded to answer this', 'Never charges, never runs an audit').

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 gives clear usage context: the key prerequisite is front-loaded ('NEEDS A KEY: mint one at https://nittim.com/keys'), and it explains when to price Audit vs Full Audit ('By default this prices Audit... `fullScan: true` prices Full Audit instead'). However, it never explicitly names sibling tools or states 'use this instead of audit_repo when you only need a price', leaving the when-not-to-use boundary implicit.

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