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

Annotations cover safety (readOnly, idempotent, openWorld, non-destructive), so the bar is lower. The description adds valuable behavioral detail: competitors are scanned one per call requiring repeated invocations, and return contents are enumerated (formula per language, average sentence length, long sentence share, hardest sentences).

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 purpose is good, but the second sentence is long and dense, packing page-type enumeration, competitor sourcing, scanning mechanics, and return values into one run-on. The language-formula list is thorough but 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?

Given output schema exists, the description needn't explain return values, yet it still enumerates key outputs. It covers the decision of what to pass for benchmarking and the multi-call competitor flow, making it complete for correct invocation. Minor gap: no explicit note that page type is inferred rather than passed as a parameter.

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, but the description adds real meaning: it explains that page type drives the target, that keyword provides context, and that competitors come from Ahrefs/Semrush top organic results and are consumed one at a time. This is beyond the schema's flat descriptions.

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 (check) and resource (readability of a page) with clear scope: measuring reading ease against a page-type-dependent target and competitor benchmark. Distinguishes itself from siblings like check_focus_keyword or check_snippet by naming the readability metric and the benchmark comparison.

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?

Clearly explains when deep benchmarking applies: 'for the best benchmark, also pass the keyword and the top results' and that competitors are scanned 'one per call, call again until done.' Missing an explicit statement of when not to use it vs. siblings, but the usage context is strong.

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