Faf Discover

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 adds genuinely new behavioral detail: the search proceeds upward from start_dir through parent directories, clarifying that this is not a flat directory lookup. It omits not-found behavior and search limits, so not a 5.

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?

Three short sentences, zero filler, front-loaded with the core action and finishing with the routing hint. Every sentence earns its place.

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?

An output schema exists, so return values need not be described, and annotations cover the safety profile. Purpose, mechanism, and ordering relative to faf_read are all present. What is missing is failure semantics (no .faf found) for a discovery tool.

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 coverage is 0% and start_dir has no schema description, so the description must carry the load. It does explain that start_dir is the origin of an upward traversal, giving the parameter real meaning. It omits the '.' default and path-format expectations, so it only partially compensates.

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 ('Find .faf files') plus the exact mechanism ('walking up from start_dir') and target artifact ('project.faf'). It explicitly names the sibling faf_read, so an agent can distinguish it without inspecting either 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?

Gives explicit workflow guidance: 'Use this before faf_read to locate the file automatically,' which tells the agent when this tool is the right choice. It does not state exclusions (e.g., what to do if no file exists or when to skip discovery), so it stops short of a full 5.

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