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

Annotations only give readOnlyHint, and the description goes well beyond it: it discloses that `lanes[]` split fields are all null when any is below 10, that `advisories` and `lanes` are NULL rather than empty/zero when no upstream feed is tracked, that `snapshot_date` can be a day stale, and that the seat-link is many-to-many so summed findings over-count. That is exactly the kind of behavioral context annotations cannot carry.

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?

It is front-loaded with a correct one-line summary, but the body is a dense wall of caveats and parenthetical internal references ('deliberately not called owned', 'issue #798') that read like spec documentation rather than agent guidance. Much context is warranted by the absent output schema, but the density costs readability.

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 must document the return shape, and it does so field-cluster by field-cluster (taxonomy fields, host counts by role, first/last seen, compliance, lanes, advisories) including null semantics and staleness. For a complex, Market-tier catalogue listing this is essentially complete.

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?

There is one parameter with 100% schema description coverage, including the 1..90 ceiling contract, so the schema carries the load and baseline 3 applies. The description only alludes to a 'trend of up to 90 UTC days' and adds no syntax or format detail 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 opening line states a specific verb and resource ('List the software library') and the body clarifies the scope as the product catalogue joined to network observations, which meaningfully distinguishes it from a single-engine lookup. However it never names a sibling (e.g. get_software, get_software_stats) to route the agent, so it falls short of the 5-level sibling differentiation.

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?

It provides interpretation guidance — trust observed `roles` over vendor `category`, do not sum `open_findings` across engines, `compliance` is null when no seat is linked — which is useful but is about reading results, not about when to choose this tool over get_software or get_software_stats. Usage is implied rather than explicitly scoped against alternatives.

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