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

Annotations already declare readOnly, idempotent, and non-destructive, so safety is covered. The description adds real context beyond them: stories come newest-first and are paged, the analysis is conditional ('when it has one'), and it imposes a downstream attribution rule ('Attribute the analysis to Mappit'). It stops short of stating page sizes or auth requirements.

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?

Two dense sentences with no filler, front-loaded with what the call returns before the usage instruction. The middle clause stacks several returned artifacts in one run-on list, but nothing is wasted.

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?

With no output schema, the description correctly carries the burden of describing the return shape (summary, paged stories, analysis sections) plus the conditional-analysis caveat. Given four params at full schema coverage and clear annotations, only minor details like default page size are left implicit.

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 id, limit, cursor and detail are already documented, making 3 the baseline. The description only reinforces the id's provenance and hints at pagination via 'paged'; it adds no format or syntax detail the schema lacks.

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 ('One storyline') and enumerates the payload it returns: summary, stories, and the AI analysis. The word 'thread'/'storyline' plus the returned fields distinguish it cleanly from get_story, list_stories, and get_digest. An agent can select it without opening the 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?

Explicitly tells the caller where the required id comes from: 'Pass an id from list_threads, whats_happening or search_mappit.' That names the concrete alternative tools that generate valid inputs, which is the main failure mode for an id-taking tool.

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