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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, so safety is covered. The description adds real behavioral value beyond the annotations: an exact credit cost model (6 credits base, +5 per further 2000 tokens). It does not state rate limits, auth needs, or timeout/truncation behavior, but cost disclosure is a meaningful addition.

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 purpose, then the cost detail in parentheses. Two sentences with essentially no filler, and the pricing parentheses are dense but information-bearing. Slightly long on the cost parenthetical relative to the operational guidance.

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?

An output schema exists, so return-value explanation is not required. Combined with the annotations, the definition covers what the tool does, the inputs, and the cost model. It leaves out any notion of page/input limits or failure behavior, which for an openWorld fetch+AI tool would be a nice addition.

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 all three parameters (url, prompt, schema) are documented in the schema itself. The description echoes that the schema parameter is optional and that a prompt guides extraction, but adds no format, syntax, or constraint detail beyond the schema. 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 (extract) and resource (structured data as JSON) and clarifies the mechanism (prompt + optional JSON Schema) which meaningfully separates it from a raw-content scrape. It does not name or contrast any sibling tool, so an agent must infer the boundary with ragfeed_scrape/ragfeed_crawl on its own.

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?

Usage is implied by 'guided by a prompt and optionally a JSON Schema' — the agent can infer this is for targeted structured extraction rather than bulk fetching. However there is no explicit when-to-use vs when-to-use-an-alternative statement, no exclusions, and no routing against the many sibling tools.

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