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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered structurally. The description adds a content profile (architecture details, verified metrics, tech stack), but an output schema exists, so this largely restates what structured data already conveys; error behavior for an unknown slug is unmentioned.

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 sentences, front-loaded with the usage trigger, then the payload summary. No filler, hedging, or redundant restatement of the name.

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 one-parameter read tool with annotations and an output schema, the definition covers trigger and content sufficiently. The only gap is what happens when the slug does not resolve (error vs empty), which is minor here.

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?

With only one parameter at 100% schema coverage, the schema already documents 'slug' fully, including concrete examples. The description's "identified by its slug" adds no new format or constraint information, 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?

States a specific verb (retrieve) and resource (a single case study by slug), and its "single case study identified by its slug" phrasing distinguishes it from the plural listing sibling get_projects without naming it. It could be sharper by explicitly contrasting with get_projects, but the scope is unambiguous.

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?

"Use this tool when retrieving the complete technical deep-dive for a single case study identified by its slug" gives a clear selection condition (singular lookup by slug). No explicit when-not guidance or named alternative such as get_projects, so it stops short of a 5.

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