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

Annotations cover the safety profile (readOnlyHint, openWorldHint, destructiveHint=false), and the description adds non-obvious behavior: results are grounded with citation URLs and competitor study-material domains are filtered out. It does not discuss rate limits or latency, and the return format is covered by the output schema, so a 4 is fair.

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 tight sentences, zero filler. The core capability is front-loaded, followed by the routing exclusion and the domain-filtering caveat.

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?

Return values are covered by the output schema, safety by annotations, and parameters by a fully covered schema, so the description's remaining job is routing and exclusion behavior — both handled explicitly. Nothing an agent needs to select or invoke this tool 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 both parameters are already documented in the schema, including the 'site' domain-filter example. The description adds no syntax or format detail beyond what the schema provides; the query guidance merely echoes the routing rule. Baseline 3 applies when the schema does the heavy lifting.

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 ('Answer open-web questions with a grounded response and citation URLs') and explicitly scopes it to non-Studocu sources. An agent can distinguish it from search-documents without opening either 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?

Explicit routing rule: use this tool for open-web questions, and use search-documents for Studocu study documents, lecture notes, summaries, or course materials. It also warns that competitor study-material domains are excluded, so the agent knows when results will be absent rather than assuming failure.

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