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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral facts — it takes no input and returns Markdown — which is the useful part for a zero-param document fetcher.

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 guide contains, followed by the when-to-use instruction and the I/O shape. The middle enumeration is long-ish but every item is substantive content discovery rather than filler.

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 a static, no-input guide with no output schema, the description supplies the return format (Markdown) and the full content inventory, which is what an agent needs to decide to call it. Slightly more detail on output size or sections would make it 5.

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?

The tool has zero parameters, so the baseline is 4. The description reinforces this by stating 'Takes no input,' leaving no ambiguity that it is invoked with an empty argument object.

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?

The description names the resource (Mappu's trip planning guide) and enumerates its actual contents — voice, day structure, timing, season, stories, food, and integration with mappu_save_trip_plan — so an agent knows exactly what the artifact is. It is distinguishable from siblings like mappu_get_audio_guide or mappu_find_walks by content domain, though it never explicitly says 'unlike X'.

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?

'Read it before planning a trip the traveler may keep in Mappu' gives a clear trigger condition and ties the guide to the mappu_save_trip_plan workflow. It lacks an explicit when-not / alternative clause, but the precondition is unambiguous.

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