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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower; the description adds pagination behavior ('Returns a cursor for the next page'), the newest-first default, and the 'crawler' source meaning. It does not describe the shape of returned stories, but with no output schema the cursor/paging disclosure is the key behavioral fact and it is stated.

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 purpose, scope and ordering in the first clause, then examples, filters, and the sibling routing last. Dense but every clause carries mapping value; slightly longer than strictly necessary due to the quoted example phrases.

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?

For an 8-optional-param, no-required-param tool with no output schema, the description supplies the ordering default, the paging contract via cursor, and the alternative tool. The only gap is it doesn't hint at what a story record contains, though paging and routing — the parts an agent must know to call correctly — are covered.

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 8 parameters including defaults and limits are already documented in the schema; the description only narrates filters ('time window, topic, language, and source crawler') plus example mappings. Baseline 3 is appropriate since the schema does the heavy lifting and the description adds no syntax beyond it.

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 ('Page through Mappit's stories'), the scope (place, country, whole world), the default ordering ('newest first'), and an alternate sort ('trending'), then names the sibling search_mappit as the tool for word/meaning lookup. An agent can distinguish this from search_mappit and whats_happening without opening a schema.

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?

Gives concrete invocation scenarios ('all the news from Kyiv this week', 'more stories' after whats_happening, stories on one topic) and an explicit exclusion with the alternative: 'To find stories by words or meaning, use search_mappit.' When-to-use and when-not-to-use are both present.

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