local_ydb_graphshard_check

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false. The description adds the read-only through 'viewer/json capabilities and tabletinfo' mechanism detail, which adds some context over the annotations. It doesn't contradict annotations. However, it doesn't describe failure modes, timeout behavior, or what happens when GraphShard doesn't exist — but with strong annotations, this is adequate.

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 two sentences and tightly written. Each clause serves a purpose: what the tool does, what it returns, and when to use it. Only minor waste — 'through viewer/json capabilities and tabletinfo' could be considered optional implementation detail, but it's informative. Well-structured and front-loaded.

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 read-only diagnostic tool with no output schema but 100% schema coverage and strong annotations, the description covers the essential ground: purpose, return values summary, and usage context. No output schema means the description should hint at returns, which it does by listing the three result elements. Adequate for a diagnostic check 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%, both parameters (profile and configPath) are fully documented in the schema. The description adds no additional parameter semantics beyond what the schema provides. Baseline 3 is appropriate since the schema fully covers parameter meaning.

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 clearly states it performs a read-only GraphShard check via viewer/json capabilities and tabletinfo, and specifies what it returns (graphShardExists, tablet ids, viewer status details). The verb 'check' plus the resource 'GraphShard' is specific. It doesn't explicitly distinguish from local_ydb_tenant_check or local_ydb_database_status, but the focused GraphShard scope differentiates it reasonably from siblings.

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 explicitly states when to use it: 'use after tenant bootstrap when GraphShard support or tablet visibility is the specific question.' This gives clear temporal context (post-bootstrap) and the specific question it answers, which implicitly distinguishes it from related check tools like tenant_check or database_status.

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