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

Annotations already declare readOnlyHint=true, so safety is covered; the description goes further with ordering (newest first) and pagination size (50 per page), which the agent needs to interpret result pages and iterate correctly. It does not address rate limits, but for a read-only list tool this is solid added context.

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?

Two front-loaded sentences carrying purpose, ordering, page size, returned fields, a usage cue and the underlying API endpoint — no filler and no repetition of structured fields.

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 listing the returned field families, and it explains pagination so the agent can page through results. It stops short of a full return-shape or pagination-termination signal, which is a minor gap for a low-complexity list 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 description coverage is 100%, so baseline is 3, but the description adds value the schema lacks: page size ('50 per page') gives the page parameter real meaning, and 'access (paid/free/draft...)' gestures at the access enum values. It does not clarify the comma-separated categories format, which the schema does, so no over-claim.

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 ('List the school's courses') and enumerates the fields returned (title, price, access, categories, author), plus ordering and page size. An agent can distinguish this from sibling get_course (single course) and list_course_users without opening either schema.

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?

Adds one genuine usage cue — 'A cheap way to confirm the credentials work' — which tells the agent this is a low-cost read useful as a health check. However, it never states when to prefer it over get_course for a single course, nor any exclusion conditions, so selection guidance stays implied.

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