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

Annotations already declare readOnlyHint and openWorldHint, yet the description adds substantial behavioral context beyond them: cups/tournaments have no numbered matchdays and instead expose `rounds` whose ids act as `competition_id`, every match is labeled with its `round`, and dates/times/scores are decoded from obfuscated glyph fonts. These are non-obvious traits an agent would otherwise mis-handle.

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-loaded with the core behavior and then the cup/round caveat and sibling routing. It is dense but every sentence contributes; slightly long, but no filler.

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 an output schema and annotations present, the description covers the three invocation modes, the cup/tournament edge case (rounds), the glyph-decoding quirk, and the alternative tools. Nothing an agent needs in order to call 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 coverage is 100%, so baseline is 3. The description still adds meaning beyond the schema: it explains the matchday_count upper bound context, what the competition_id means for cup competitions (a round id works in its place), and the date-vs-matchday exclusivity rationale. This is meaningful added semantics, though the schema already carries most of the per-parameter detail.

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 (returns the matches of a competition's matchday) and explicitly names the three selection modes: current matchday, numbered matchday, or matchday around a date. It also names the sibling tools it is not (fussballde_match_plan and fussballde_match), so an agent can distinguish it 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?

Explicitly routes the agent: use fussballde_match_plan for the whole season schedule, fussballde_match for one match in detail. It also tells the agent which parameter mode to pick (omit both for current, matchday for a number, date for a window) and flags the mutual exclusion, leaving little to inference.

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