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

Annotations provide readOnlyHint: true and destructiveHint: false, and the description adds value by stating 'Read-only and spends no quota,' which is not derivable from annotations alone. Also explains what each field in the response represents, especially the diagnostic relevance of last_run_error.

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?

Front-loaded with purpose and ordering, then follows with usage guidance and field details. Slightly wordy in the middle section listing fields—could be tightened without losing meaning, but overall efficient for the information conveyed.

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?

Despite no output schema, the description fully documents return fields (schedules, total, limit, offset) and explains key schedule row attributes. The tool is simple (2 optional params, no nested objects), and the description covers all aspects needed for correct invocation and interpretation.

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 baseline is 3. The description adds value by implying that the tool supports pagination (returns offset and limit in response) and confirms default values (limit defaults to 50, offset to 0) though not explicitly stated. A small deduction because the description does not directly tie limit/offset to pagination behavior or explain the return structure fully.

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 uses specific verbs ('List') and resource ('recurring render schedules') while distinguishing from siblings like create_schedule and delete_schedule by mentioning the id needed for deletion. Scope is confined to 'this account' and ordering is explicitly 'newest first'.

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?

Explicitly states when to use: before creating a duplicate schedule and for diagnosing a non-producing schedule. Lists what each row contains (enabled, schedule, timezone, etc.) and clarifies that last_run_error shows delivery or quota failures, giving the agent clear decision rules.

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