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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavior: results are ranked by score and heat, each carries a summary, heat and source links, and a total match count is returned. It does not mention rate limits or behavior on zero matches, but the extra operational detail is solid.

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?

Dense and front-loaded: purpose, then concrete usage examples, then parameters with defaults and caps, then return shape — all in a few lines with no filler. Every sentence 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 4-parameter read tool with full schema coverage, annotations and an output schema, the description supplies enough: query semantics, time window, result cap and ranking. The only omission is any mention of the niche parameter, though the schema covers it and it has a single default value.

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 the schema already documents q, hours and limit with the same defaults and ceilings the description repeats. The description's one additive point is the AND semantics of q ("words that must all appear"), which the schema also states, and it omits niche entirely. 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 opens with a specific verb and resource ("Search stored events by words") and backs it with concrete example queries that make the intent unmistakable. It does not, however, explicitly distinguish itself from siblings like latest_events or daily_digest, which appear to be adjacent retrieval 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?

Three sample questions ("what happened with Claude Code this week?", "any news about Gemini CLI?", "Codex releases") give a clear sense of when this tool applies. There is no explicit when-not guidance or named alternative for browsing the newest events versus searching, so the routing against latest_events is left to inference.

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