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 real behavior beyond them: output is a per-week plan, it is not a stateful tracker, and 'practice links to Dutch Fluency always come with alternatives' discloses a deliberate content guarantee about the returned links.

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?

Three sentences, zero padding, and the core deliverable is front-loaded before the usage trigger and the exclusion. The closing clause about Dutch Fluency is narrow but earns its place as a behavioral guarantee.

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 sketch the return shape (a week-by-week path of real courses, tutors, apps and trials) and scopes out progress tracking. It remains thin on input value formats and does not say whether any parameter is effectively needed despite zero required fields, but nothing critical for a safe, informed call 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 coverage is 0% across five parameters, so the description must carry the load. It does map semantic meaning onto each input ('city, goal, current level, weekly hours and deadline'), and 'deadline' usefully clarifies that move_or_exam_date accepts either a relocation or exam date. However it gives no value formats or ranges (level vocabulary, date format, hours bounds), leaving the agent to guess.

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 deliverable: a 'week-by-week study path' that 'points to real courses, tutors, apps and trials' for enumerated inputs. It partially differentiates from siblings by ruling out one adjacent function ('Not a progress tracker'), though it never names tdd_move_plan or tdd_shortlist, which is where an agent would look first.

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?

'Use it when someone asks how to get from one level to another or how to prepare for an exam' gives concrete trigger scenarios, and 'Not a progress tracker' supplies one explicit exclusion. It stops short of naming an alternative tool for the excluded case, so the routing is clear but not complete.

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