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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is largely covered. The description usefully resolves the apparent tension between the 'log' name and readOnlyHint by stating it opens nothing by itself and only returns instructions, plus that no public API exists. It adds no detail on rate limits or auth for the subsequent browser step, so it extends beyond annotations only modestly beyond that one key clarification.

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 and the 'opens nothing by itself' clarification are front-loaded, which is good. However, the closing sentence 'CoachingPortal's official API: CoachingPortal publishes no public API.' is awkward and repeats the product name redundantly, and 'from ChatGPT, Claude or any AI agent' adds little.

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?

With no output schema, the description does the necessary work of saying what the invocation yields (step-by-step screens, buttons, fields) and what the agent must do next via cotlet_browser_* tools. That is sufficient for a zero-parameter guidance tool, though it could be slightly clearer about the response format (text versus structured).

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The prose correctly implies no input is required.

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 names a specific verb and resource (log personal progress in the user's own CoachingPortal account) and, crucially, clarifies that the tool returns instructions rather than performing the action — 'opens nothing by itself' and 'returns how to do it ... step by step'. That reframes what would otherwise read as a mutation tool. It does not explicitly name a sibling such as coachingportal_add_progress_entry to contrast with, so it falls short of a 5.

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?

It gives a concrete workflow: call this to get step-by-step guidance, then execute with cotlet_browser_* tools in the user's CoachingPortal Cloud Browser. It also explains why this route is required (CoachingPortal publishes no public API). It stops short of stating when not to use it versus a direct sibling like add_progress_entry.

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