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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive safety. The description adds useful behavioral and scope context beyond those: it names the underlying SPARQL endpoint, specifies the two EU programmes covered, lists returned fields (grant agreement ID, RCN, title, dates, status), and gives thematic coverage. No contradiction with 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?

The description is three sentences, front-loaded with the action and scope, then filters, then return fields and the follow-up tool. Every sentence earns its place with zero 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?

For a search tool with an output schema and rich annotations, the description is complete: it explains what is searched, what filters exist, what comes back, what thematic areas are covered, and how to chain to project_details. Nothing essential for selecting or invoking the tool 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 description coverage is 100% with detailed parameter explanations (e.g., status enum values spelled out, year range semantics, limit bounds). The description's filter mentions ('keywords in the project title, lifecycle status..., and start year range') largely mirror the schema rather than adding new meaning, so the 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 starts with a specific verb and resource: 'Search 80,000+ EU-funded research projects from Horizon Europe (2021–2027) and H2020 (2014–2020).' It clearly scopes the tool as a project-search against a named SPARQL endpoint and distinguishes it from sibling project_details with a direct pointer: 'Use the `id` field with cordis.research.project_details to get full project data.'

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 gives strong context: which funding programmes are covered, what filters exist, and explicitly routes the agent to project_details when full data is needed. It does not explicitly state when not to use this tool or contrast with project_publications/organisation_search, but the resource type (projects) makes the primary use case unambiguous.

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