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

With no annotations, the description carries the full burden and does well on access control: it discloses the paid-plan requirement, excludes verification-only plans, and explains both auth paths (X-API-Key header or api_key argument fallback). It stops short of describing read-only semantics, return shape, or rate limits.

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?

Four tight sentences, zero filler, front-loaded with purpose and scope before the exclusivity rule and auth details. Every sentence conveys a constraint the caller needs.

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?

Covers the key risk areas for a 9-param, no-annotation, no-output-schema tool: resource scope, mutual exclusivity, and authentication/plan gating. The one remaining gap is that nothing describes the shape of returned commit records, which the absent output schema cannot compensate for.

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 already documents every parameter and the oneOf mutual-exclusivity constraint. The description restates the 'exactly one' rule and adds rationale for api_key, but contributes little beyond the structured data. Baseline 3 is appropriate.

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 ('Returns git commit history') and explicitly distinguishes the two scopes: project-wide (aggregated across all vaults) vs. single vault. No sibling tool in the list covers git history, so the agent can identify this tool immediately.

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?

Explicitly states the selection rule: 'Provide exactly one of project_id or vault_id,' with each parameter's semantic scope documented. It does not name alternative tools for adjacent needs, but for a uniquely-scoped resource tool the routing guidance is clear.

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