why

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

No annotations are provided, so the description carries the full burden. It says nothing about what the explanation looks like, whether it is derived from stored records, whether it requires prior context, or what the cost/latency profile is; only the acceptable query forms are disclosed, which is a small behavioral hint.

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?

A single compact sentence with the key input clarification front-loaded and no filler. It is not padded, though the terseness is part of why other dimensions are under-specified.

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 annotations, no output schema, three parameters and zero schema descriptions, the description is too thin for the tool's apparent complexity. An agent still cannot tell what an 'explanation' contains, how ids are resolved, or what 'project' and 'max_tokens' do.

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 must compensate, and it only covers one of three parameters: 'query' is clarified as free text or an id of a symbol, memory, or session. The 'project' and 'max_tokens' parameters receive no explanation at all, leaving a substantial coverage gap.

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 verb is 'explain' and the object is 'the logic behind something', which is broad enough to be ambiguous on its own. The clause naming the accepted query forms (free text or symbol/memory/session id) gives a clearer picture of scope, but the phrase 'something' keeps the purpose fuzzy rather than crisply differentiated from siblings like 'who' or 'search'.

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?

There is no guidance on when to call this versus 'search', 'expand', 'remember', or 'who'. The description lists what the query can contain but never states the condition or situation that should select this tool over the many explanation-adjacent siblings.

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