Read a Phygital Brain file

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds genuinely new behavior: the error cases (missing file, folder, path outside skills folder return an error that says so) and the strict read scope ('never the person's brain, and changes nothing'). It stops short of describing pagination or size limits, but for a single-file read that is minor.

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?

Front-loads what is returned, then usage, then failure modes and scope in four tight sentences. Each sentence contributes, though the brain-file exclusion is asserted in both the description and the schema example, a mild redundancy.

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?

No output schema exists, and the description supplies the return value ('return its full text'), the error behavior, and the scoping boundary. For a one-parameter read tool with full annotation coverage, nothing an agent needs to invoke it correctly is missing.

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% and the property description already explains the skills-folder path and the brain-folder exclusion with examples, so the description's path scoping largely restates structured data. Baseline 3 is appropriate since the schema does the heavy lifting for the single parameter.

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?

Names a specific verb (read) and resource (one of Phygital Brain's own files), enumerates what kinds of files it covers (form, template, language file, skill), and explicitly contrasts itself with phygital_brain_list_files and the person's brain. An agent can distinguish it from its siblings without opening any 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 an explicit trigger ('use it when the instructions from phygital_brain_start name a file') plus a fallback routing rule ('if you don't know the exact name, list the folder with phygital_brain_list_files first'). Both the when and the alternative are stated, not implied.

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