project_instructions

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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds valuable behavioral nuance beyond annotations: it explicitly states that it does not silently merge conflicting rules, provides provenance, and explains empty-path behavior. This gives the agent critical safety-awareness without contradicting the annotations.

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?

The description is extremely concise: three sentences that front-load the purpose, then highlight behavioral traits, then provide parameter guidance. Every sentence adds value without fluff, making it easy for an agent to parse quickly.

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?

The tool has 5 optional parameters and an output schema. Description covers core behavior, conflict handling, and key parameter semantics. Notable omissions like max_bytes and project are not critical given the output schema and the clarity of the overall context, making this a well-rounded description.

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 0%, so the description must compensate. It does explain include_agent_requested and lease_id, and describes the semantics of empty paths, but leaves project and max_bytes undocumented. This is partial compensation; the agent would benefit from more parameter-level detail.

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 uses the specific verb 'Return' with a clear resource: 'applicable project instructions for path(s)' with provenance. It distinguishes itself from sibling tools like project_skills_list and project_skill_read by focusing on instructions rather than skills, and also clarifies its scope (always-on vs. rule files).

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?

Provides clear context on when to use the tool: when you need project instructions, with specific guidance for empty paths and the include_agent_requested flag. It does not explicitly name alternatives or exclusions, but the context is strong enough for an agent to decide when this tool is relevant.

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