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

The safety sentence ('Closed-world: operates within the authenticated user's Tripsy account') merely restates the supplied openWorldHint=false annotation rather than adding new information. The description says nothing about not-found behavior, required permissions, or what happens when trip_id and id mismatch, so beyond the annotations it contributes essentially nothing.

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 short sentences, with the core action front-loaded and no filler. The safety clause is redundant boilerplate but does not obscure the purpose.

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?

This is a simple two-parameter read with an output schema, so return values need not be explained. However, the description omits not-found/error semantics and the need for both identifiers, leaving the definition only minimally adequate for correct invocation.

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 both trip_id and id are already documented in the schema. The description only echoes the 'by id' lookup and says nothing about the composite scoping (trip_id plus hosting id) or id formats, which is the baseline 3 when the schema does the heavy lifting.

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 states a specific verb and resource: 'Fetch one Tripsy hosting by id.' That clearly separates it from the sibling list/create/update/delete operations on hostings. It does not explicitly name those siblings, so it falls short of 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?

There is no guidance on when to use this tool versus tripsy_hostings_list or the other hosting tools, and no mention that a trip_id scope is required to resolve the hosting. The agent must infer the retrieval use case purely from 'Fetch one ... by id.'

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