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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description goes well beyond that by disclosing determinism, that timezone/year-ambiguous timestamps are excluded, that input is not retained, and that returned evidence is untrusted data rather than instructions. These are substantive behavioral and trust-boundary facts an agent cannot get from 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?

Four short sentences, each carrying distinct information, with the core capability front-loaded and constraints following. No filler, though the enumeration of behaviors is slightly clipped and could be structured as a short list for faster scanning.

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?

With no output schema, the description compensates by naming what is returned (format counts, severity counts, timestamp ranges), and it covers retention and prompt-injection safety. The one gap is that the format parameter's accepted values are never explained, which matters because it is the only optional input.

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 50%: text is documented in the schema, while format is an enum with no description. The description mentions the 1,000-line cap but that duplicates the schema's own text, and it never explains what 'auto' does or why one would choose rfc5424 over rfc3164. Baseline 3 is appropriate given the schema carries half the load.

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+resource: counting formats/severities and finding unambiguous timestamp ranges over supplied log lines. That is clearly distinct from validate_config or analyze_http_trace, but it never names the closest sibling, parse_logs, so the agent must infer the boundary between summarizing and parsing.

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?

Implied usage is clear from 'up to 1,000 supplied log lines' (use it on pasted log text), and the deterministic/no-AI framing hints this is the tool for plain counting rather than interpretation. However, there is no explicit when-to-use versus parse_logs or extract_ci_failures, and no exclusions.

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