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

Annotations already cover the safety profile (readOnly, openWorld, non-destructive), and the description adds real operational context: a curated host allowlist, robots.txt and redirect gating, no browser rendering/bypass, no key/credits/wallet needed. It stops short of describing compaction behavior or failure modes.

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 a compact clause chain of constraints. The closing 'Existing source and input limits apply' is vague filler that costs it a point.

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 an output schema exists (so return values need not be explained) and annotations carry the safety profile, the description covers host scope, gating behavior, and cost model adequately. What 'compact' actually produces is left unstated but is inferable from the pack format.

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 67% and the description adds no parameter-level meaning - it never explains url or maxChars, only gesturing at 'Existing source and input limits apply'. With the schema doing most of the work, this is a baseline 3.

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 ('Retrieve and compact ... HTML page') and narrows scope to docs.python.org, so the agent knows exactly what it returns. It does not explicitly distinguish itself from near-siblings like web_readable_fetch or web_page_pack, which keeps it from a 5.

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?

Constraints imply the use case ('Curated HTTPS host only; robots and redirect checks'), and the free-tier note is useful context, but there is no explicit when-to-use or when-to-prefer-an-alternative statement against web_readable_fetch/web_page_pack.

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