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

Annotations provide readOnlyHint=true, so the description need not repeat that. It adds useful behavioral context by specifying the supported time periods and that it returns statistics, which goes beyond the schema. However, it doesn't mention return format or aggregation details, which could be useful but is not critical given the read-only nature.

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?

The description is a single sentence that is concise and directly conveys the core purpose and supported periods. It is appropriately sized, though it could be slightly more detailed on usage without being verbose.

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 read-only stats tool with a clear schema and annotations, the description is adequate. It covers the main parameters and purpose, but lacks information on the response structure (since no output schema) and could benefit from clarifying what 'response time statistics' includes, such as averages or percentiles. Given the simplicity, this is acceptable but not exceptional.

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 both parameters are well-documented. The description adds a little by stating 'uptime and response time statistics' which clarifies the kind of data, but the schema already specifies period values and monitor_id purpose. Therefore, baseline 3 is appropriate.

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 clearly states the tool fetches uptime and response time statistics for a specific monitor, which conveys the purpose. However, it doesn't explicitly differentiate from sibling tools like get-response-time-chart or summarize-health, which could also involve stats.

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?

The description implies usage is for retrieving historical uptime stats, but there is no explicit guidance on when to choose this over alternatives like get-response-time-chart or summarize-health. It mentions supported periods (24h, 30d) which helps with selecting the period parameter, but no exclusions or alternative routing.

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