set_frontmatter

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

With no annotations, the description carries the full burden. It usefully discloses that content is preserved and that a null value deletes the field, but says nothing about permissions, whether it merges vs overwrites frontmatter, or behavior on files without existing frontmatter.

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 the core action, then adds example, null semantics, and a preference hint. Every clause earns its place; slightly dense but no padding.

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 no explanation, and the two parameters are well covered. For a 2-param mutation tool the description is nearly complete, with only edge-case behaviors left unstated.

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 the 'fields' object is nested, yet the description compensates: it lists example keys (description, tags, related, name), shows a concrete call, and defines the null-deletes semantic that the schema does not. path is illustrated via the example.

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+resource ('Cambia campos del frontmatter') with an explicit scope note ('sin tocar el contenido') that separates it from whole-file rewrites. It is clear what it does, though it does not name a sibling like write_file 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?

Explicitly recommends itself over rewriting the file 'cuando solo cambia un metadato', giving a clear condition that selects it against the write_file/append_file family. No when-not guidance beyond that, but the alternative is named.

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