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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds that results are 'weekly' availability slots with day/time fields, which is useful content context. It does not add behavioral detail beyond that (e.g., that results are paginated), and the trailing 'GET /availabilities' mostly restates the read-only annotation.

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 short, front-loaded sentences with no filler; the purpose, usage cue, and endpoint are each stated once. Nothing could be removed without losing information.

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 simple read-only list tool with fully-covered schema and no output schema, the description supplies both purpose and return-content shape ('day of week + start/end time') and a usage cue, leaving little an agent needs. Only the lack of any pagination note keeps it from being 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?

Schema description coverage is 100%, so all five parameters (day, page, per_page, direction, employee_id) are already fully documented in the schema. The description's mention of 'day of week' loosely maps to one param but adds no format or default detail beyond what the schema provides, so the baseline 3 applies.

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?

'List teachers' weekly availability slots (day of week + start/end time)' uses a specific verb and resource and even sketches the data shape. No sibling tool deals with availability, so it stands cleanly apart from teachworks_list_employees and the other list_* tools.

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?

'Use before scheduling a lesson' gives a concrete use context that tells the agent when this call is relevant. It stops short of naming alternatives or exclusions, but for a uniquely-purposed list tool that is a minor gap.

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