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

Annotations already declare readOnlyHint=true, so the 'Read-only' tag is partly redundant. However, with no output schema, the description usefully discloses what the caller gets back (totals by status/type, failure rate, error excerpts), which is real context beyond the annotation. It omits any note on rate limits or freshness of the history.

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 the core action, then the return contents, then usage guidance and the sibling alternative. Two dense sentences with no filler; 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 read-only aggregate with a fully described schema and no output schema, the description covers purpose, return shape, temporal scope, and alternatives. An agent has everything needed to select and invoke it correctly.

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 cluster_id, type, and window_days are already documented in the schema. The description only restates the default 7-day window, adding no syntax or nuance beyond the schema's own bounds (1-30). 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?

States a specific verb (aggregate), resource (deployment/platform execution history), and scope (this cluster, time window), and enumerates the aggregates produced: totals by status/type, failure rate, most-failing names, recent failures. It explicitly distinguishes itself from the closest sibling, get_execution_details.

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?

It names concrete questions the tool answers ('has this been failing for a while', 'what keeps breaking') and the correlation use case, then routes the agent elsewhere for single-execution detail via 'use get_execution_details instead'. When-to-use and an alternative are both explicit.

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