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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds a useful cost hint ('Cheap') and the backing GET endpoint, but says nothing about rate limits, response shape beyond an implied count, or filtering behavior on large tables. Useful but modest added value over the annotations.

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 tight sentences with the purpose front-loaded, followed by the cost/workflow tip and the endpoint. Nothing is redundant and every clause carries 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 two-parameter, read-only count tool with no output schema, the description covers purpose, filter reuse, and cost guidance. The return value (a count) is implied clearly enough, though the exact response envelope is not spelled out.

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 real meaning by noting the filter uses the same syntax as method_query_records — context the schema's bare 'Filter expression' lacks. The table parameter is left to the schema, which documents it well.

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: counting records in a table, with an optional filter. It names method_query_records in passing, which implicitly separates it from the record-returning sibling, though it never explicitly contrasts the two. An agent can identify it as the count-only tool without opening the 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?

'Cheap: call it before paging through a big table' gives an explicit when-to-use condition and a practical workflow context. It also points to method_query_records for the filter syntax, tying it to the alternative. It doesn't state when NOT to use it, keeping it short of a 5.

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