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

Annotations already cover the safety profile (readOnlyHint=true), so the description's contribution is field-level behavior: it lists exactly what comes back and warns that include_text can be long. It also discloses a real limitation — that SureChEMBL no longer returns CPC codes, citations or legal events — which prevents an agent from planning around fields that will not appear. That is meaningful context beyond the annotations.

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?

Two dense sentences with no filler; the returned-field inventory comes first and the negative capability note is placed at the end as a caveat. It could be trimmed slightly, but nearly every clause carries information.

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 must carry the return shape, and it does so by enumerating the fields returned. The main remaining gap is error/not-found behavior for an invalid doc_id, which is minor for a simple two-parameter read tool.

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 100%, including format examples for doc_id and a default note for include_text, so the schema already carries the parameter burden. The description reinforces include_text ('optionally the claims and description text') and its length risk, but adds no new syntax or constraint information. Baseline 3 applies.

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 identifies the resource precisely — a single patent document from SureChEMBL — and enumerates its contents (title, dates, applicants, inventors, family, priority claims, compound count, abstract, optional full text). Combined with the required doc_id, an agent can tell this is a single-document fetch rather than a search, but the description never explicitly contrasts itself with siblings such as surechembl_search_patents or surechembl_patents_for_compound.

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: the presence of a required doc_id signals 'call this when you already have a publication number'. There is no explicit when-to-use statement, no pointer to the sibling search tools for obtaining a doc_id in the first place, and no stated exclusions.

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