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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld). The description adds real behavioral value on top: the shape of the result (twenty registers, each carrying the source provision) and the semantic trap about pre- vs post-registration windows. It does not disclose response format details or fallback behavior for unknown offices.

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 answer, then the return shape, then the trap, then accepted input formats. Every sentence carries information, though the 'trap' paragraph is somewhat discursive relative to the one-parameter lookup it describes.

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?

There is no output schema, so the description correctly describes what comes back (twenty registers plus the governing provision) and what the tool is for. Minor gap: it does not state units or granularity of the window (days vs months) or what happens for an unsupported office.

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 description coverage is 0%, so the description carries the full burden for the single 'office' parameter, and it does: it accepts a country name, an office name, or a two-letter code, with concrete examples ('japan', 'JP', 'EU'). This is exactly the compensating detail the schema lacks.

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 resource (opposition window per trademark office) with the two dimensions it returns — duration and trigger point. No sibling tool covers this, so the agent can route to it unambiguously.

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?

The description frames the use case explicitly: determining opposition deadlines and avoiding the mistake of applying one office's rule to another. It lists the exception offices (Switzerland, Germany, Japan, Sweden) that behave differently, which is effectively usage guidance. It does not name a sibling alternative or a when-not-to-use condition, so it stops short of a 5.

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