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

With no annotations provided, the description carries full behavioral disclosure and does so thoroughly. It reveals that GmSSL encrypted PEM import has no password check, that wrong passwords may silently produce garbage keys, that a built-in N-1 probe performs a sign/encrypt round-trip verification (probe_verified=true) before output, and that a wrong password yields the error 'SM9 extract user key failed'. This is far beyond a typical description.

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 dense but front-loaded with purpose and standard, then lists inputs, then explains the verification probe and outputs. Every sentence adds non-redundant information. It is slightly marred by the duplicated '[sm9_ibc]' prefix, which is a minor formatting flaw, but overall it is efficiently structured.

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 crypto key-extraction tool with no annotations and no output schema, the description is remarkably complete: it covers input semantics, the prerequisite relationship to GenerateSm9, the verification mechanism, the output (user_private_key_in_pem), and the failure mode. Nothing needed for a caller to use the 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 the baseline is 3. The description adds meaningful semantics beyond the schema: master_private_key_in_pem must be GenerateSm9 output, private_key_password is reused to encrypt the extracted user key, and identity is the being-issued user's identifier bounded to 1-63 UTF-8 bytes. These extra details clarify parameter relationships that schema descriptions do not fully convey.

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 specifies a clear verb and resource: KGC extracts SM9 user private key by identifier (GM/T 0044). It differentiates from siblings by explicitly sourcing master_private_key_in_pem from GenerateSm9 output and by positioning the tool as the key-issuance step, distinct from sm9_sign/verify/encryption/decryption which consume the key.

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 conveys clear usage context: it is the KGC-side step to derive a user key from an already-generated encrypted master key, with identity and key_kind as the distinguishing inputs. It implicitly distinguishes from generate_sm9 by naming the master key as a required input, though it does not explicitly state when not to use this tool or name alternatives.

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