log_progress

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

Annotations already declare a non-read, non-idempotent, non-destructive write to a closed world. The description adds genuine value beyond them: the exact file path, the append semantics, and the conditional behavior where a missing '## ' prefix causes the date and time to be generated as the title.

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 purpose is front-loaded in one sentence, and the Args block adds only the format detail an agent actually needs. The docstring indentation and stray line break make it slightly less clean than it could be, but nothing is 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 one-parameter schema is fully explained in prose. Remaining gaps are secondary: behavior if the file or directory is missing, and confirmation that repeated calls create duplicate entries (consistent with idempotentHint=false but 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% for the single `entry` parameter, so the description must carry the load and largely does: it specifies the markdown format, the required header pattern ('## YYYY-MM-DD · mode · exercise'), and the fallback title auto-generation. It omits whether trailing newlines are added or whether mode must match an enum-like value.

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 with the concrete target ('Appends a session to the progress log (~/VoiceCoach/progress.md)'), which implicitly distinguishes it from read_progress. It stops short of explicitly naming the sibling for contrast, but the append-vs-read distinction 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?

Usage is only implied: an agent can infer this is for recording a completed session, and the sibling list contains read_progress. There is no explicit when-to-use statement, no mention of prerequisites (does the file need to exist?), and no exclusion of alternatives.

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