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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered; the description adds genuinely new behavioral context with "Needs the owner signed in", an auth constraint not present in any structured field. It also discloses the shape of returned data, though it says nothing about behavior when the license is absent or when app_id matches many licenses.

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?

Three sentences, no filler, with the lookup-key guidance and auth prerequisite placed after the payload summary. The opening sentence is a long comma-separated field list rather than a verb-led statement of purpose, which slightly delays the agent's recognition of what the tool does.

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 carries the return-value burden and does so thoroughly by enumerating the license facets. The remaining gaps — error behavior for unknown ids and result volume when app_id returns multiple licenses — are small but real for a lookup 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%, so the baseline is 3, but the description adds value beyond the schema: it names get_account as an additional source for license_id (the schema mentions only list_owned) and frames the two parameters as alternatives ("license_id ... or app_id"), clarifying the either/or selection the schema leaves implicit.

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 enumerates exactly what a license record contains — type, billing, status, update expiry, covered versions, sites, renewal/upgrade availability — which makes the resource unmistakable and implicitly separates it from the list-style sibling list_owned, which it names as an id source. It never states the verb outright ("get/return"), relying on the title to supply that, which keeps it just short of a 5.

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 gives concrete invocation guidance for the ids ("license_id (from list_owned or get_account)" or "app_id (every license for that app)"), so an agent knows where to get the inputs, and it flags the sign-in prerequisite. However, it never says when to choose this over get_app or list_owned — the comparison is left to inference.

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