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

Beyond the readOnly/idempotent annotations, the description adds concrete behavioral context: no network call for common licences, fallback API behavior, risk-level assumptions based on proprietary/commercial use, a 60/minute rate limit, and no auth requirement. This gives the agent an accurate operational model with no contradictions.

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 compact and front-loaded: purpose, output summary, behavioral caveats, rate limit, auth, target audience, and fallback reporting instructions all appear without filler. Each sentence adds operational value.

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 single-parameter, read-only, idempotent tool with an output schema, the description covers inputs, outputs, network behavior, risk assumptions, rate limiting, auth, and intended users. An agent has sufficient information to select and invoke the tool correctly in context.

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 schema fully documents spdx_id with examples (MIT, Apache-2.0, GPL-3.0) and marks it required, so parameter coverage is 100%. The description reinforces that the identifier can be any SPDX licence and mentions common vs rare identifiers, but adds no new parameter-level semantics beyond the schema.

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 clearly identifies the tool's resource and function: it analyses any SPDX licence identifier and returns obligations, permissions, limitations, risk level, and OSI/FSF status. It is distinct from package-oriented siblings like security_fetch_package_licence, though it does not explicitly name alternatives.

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 a specific use case: security engineers and developers understanding what a licence allows before including a dependency. It also explains operational behavior like the static top-50 bundle and fallback to spdx.org, but it does not state when not to use the tool or name sibling alternatives.

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