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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely useful behavior beyond that: a shared fetch cache ('the first reader pays for the fetch and everyone after them reads it out of the database') and the degraded-response contract (summary plus a reason such as publisher-opt-out, never an error). Those additions are valuable but the caching detail is presented twice with slight redundancy.

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 what the tool returns, then the inputs, then the fallback contract — a sensible order. The clause 'so the publisher is asked once rather than once per view' restates the preceding clause and could be cut without loss.

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?

There is no output schema, so the description carries the return-shape burden and does so fully: prose full text normally, or summary plus a reason on paywall, outage, or opt-out. Combined with the inline parameter schema, an agent has everything needed to call it and interpret both success and degraded results.

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 both parameters are already documented, and the description only repeats that guid comes from other tools while naming which ones. It adds no format, syntax, or validity detail beyond the schema's own 'as returned by the other tools'.

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 and resource ('The full text of one post, extracted from the publisher's own page and returned as prose'), which immediately distinguishes it from feed/topic listing siblings that would return summaries. An agent can tell this is the full-content read versus a metadata read.

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?

Implies when to use it by naming the source of its two inputs ('the feed slug and post guid that search, get_feed and topic_posts return'), and the fallback paragraph tells the agent what happens when full text is unavailable. It stops short of stating explicit exclusions or contrasting itself with a summary-only sibling, so no 5.

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