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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description usefully discloses what content sections come back (challenge, idea, stack, 3D models, key facts), which matters since there is no output schema, but says nothing about structure, depth, or behavior for unknown slugs.

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?

A single dense sentence with the resource first and the returned content front-loaded. Every clause adds information; 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?

For a simple two-parameter read tool with annotations and a fully documented schema, the description is nearly sufficient, and enumerating the returned sections substitutes for the missing output schema. It stops short of covering failure behavior or how deep the case study content goes.

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%; the lang enum explicitly instructs use of the user's language and the slug documents its enumerated values. The description adds no parameter meaning beyond the schema, so baseline 3 applies.

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 a specific verb+resource ('Full case study of one project') and enumerates the contents (challenge, idea, stack, 3D models, key facts). It implicitly distinguishes itself from the listing sibling by scoping to 'one project', though it never names hilo_list_projects directly.

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?

Usage is only implied: an agent infers it should call this when it wants detail on a single project, and the slug's enumerated values point back to hilo_list_projects. There is no explicit when-to-use/when-not or routing to an alternative such as hilo_find_relevant_work.

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