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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally. The description adds genuinely useful context the annotations do not: the endpoint, the 10-credit Tier 1 cost, and the group. It does not disclose result ordering, chunk granularity, or hit limits, so it stops short of rich behavioral context.

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?

Four short, front-loaded lines with no prose padding; the core purpose statement leads. The "Required" line is redundant with the schema, which is the only real waste.

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 tool taking a deeply nested chart object plus three tuning parameters, the description is thin: no sense of ranking/scoring semantics, no indication of what the chunks are drawn from, and no guidance on choosing topK. An output schema exists so return format need not be explained, but the retrieval behavior itself is left entirely to inference.

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 a middling 60%. The description adds no parameter meaning at all — it only echoes the two required names already enforced by the schema — and says nothing about topK's default/range, the fields compact projection, or precision, the parameter most likely to be misused.

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?

Names the mechanism (keyword-tag scoring) and the corpus (chart chunks), which goes beyond simply restating the tool name. However, it never says what the tool returns or what a "chunk" is, so an agent cannot tell whether this is a document retriever over interpretive text or a query over computed chart 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 only usage-adjacent line is "[Required: query, chart]", which merely restates the schema's required list. There is no statement of when to reach for this tool rather than a direct retrieval sibling (e.g. astroway_mcp_multi_chart_context), and no prerequisites or exclusions.

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